This is quite a good story although I have not yet resolved all the detail. The following  uses excerpts from this website http://www.duffus.com/sundaynews5_5_02/duffus_of_dalclaverhouse.htm

JAMES COUTTS-DUFFUS OF DALCLAVERHOUSE, formerly of The Mansion of Claverhouse, by Dundee, Angus, and of The Priory, Rotherfield, Sussex, holder in life rent of the superiority of the lands, estate and feudal fief of Dalclaverhouse (which he made over to his sister by Deed of Gift 1965), FRSA, FSA Scot, served in World War II 1939-45 with R E (despatches), assumed surname of COUTTS in addition to and before his patronymic 1946, and discontinued same and was recognised by Lord Lyon King of Arms in style of DUFFUS of DALCLAVERHOUSE and matric arms 6 March 1957 b 3 June, 1919, educ Arnhall Coll Sch, Dundee.

Lineage–Duffus is a surname derived from the lands and village of that name in Morayshire. Possibly the first of the family to settle in Perthshire was Andrew Duffus, who witnessed a Hay Charter 1608.The first proven ancestor is–THOMAS DUFFUS, in Rattray, Perthshire, m Elisabeth Hodge, and had issue, a son, JAMES DUFFUS, in Rattray, b 4 June, 1794, m (confirmed before the Kirk Session of Rattray, Perthshire, 15 April, 1819), Jean Souter, and had issue,

1a JAMES DUFFUS, of whom presently.

2a Thomas DUFFUS, b 14 Jan. 1825; had issue.

3a George DUFFUS , b 12 July, 1829, m., and was killed in America.

4a William DUFFUS, m three times, and had issue. .

The eldest son, JAMES DUFFUS, of Westport House, Cupar, Fife, JP, a Bailie and Dean of Guild of Cupar, b 23 Feb. 1822, m 19 Sept. 1848, Ann (d 2 Dec. 1904), yst dau of John Coutts, a Bailie of Cupar, of Bonnygate, Cupar, Fifeshire, and d 3 Dec. 1916, having had issue,

1a JAMES DUFFUS, of whom presently.

2a John Coutts DUFFUS, of Penniwells, Elstree, Herts, and of Westport House, Freeman of Cupar (1927), Pres of Overseas Civilian advsr/y Bd, b 14 Feb. 1863; d unm. 25 Jan. 1933.

.The elder son. JAMES DUFFUS, of Bogie House, Fife, Daleham Gardens, Hampstead, London, and of Clive Row, Calcutta, b 17 March, 1850, m 10 June, 1890, Rosetta Elizabeth (d 26 April, 1948), dau of John Black, JP, Provost of Greenock 1899-1901, hon. Sheriff Substitute of Renfrewshire and Bute, of Copthorn, Greenock, Renfrewshire, and d 1 May, 1904, having had issue,

1a JAMES MONTAGUE COUTTS, of whom presently.

2a John Noel DUFFUS, b 25 Dec. 1899; d 14 Feb. 1904.

1a Frances Hedger DUFFUS, Cllr. St. Andrews 1929-32, b 1 Dec. 1894, m 1stly, 29 April, 1915, Lancelot Turtle Montgomery, L.DS., R.C.S. Eng., of The Cottage, Bays Hill, Elstree, Herts (d 25 April, 1922), son of Johnston Montgomery, of Belfast, and had issue, 1b • John Coutts DUFFUS, MI.C.E, MMech.E, Lt.-Col-(ret) R.E [Drum Brae House, 12, Drum Brae South, Edinburgh], b 19 Dec. 1920, educ Glenalmond, R.MA. Woolwich, and St. Catharine's Coll Camb. (BA. 1949, MA. 1959), m 15 Sept. 1945, • Catherine Herdman, dau of Alexander Robert Campbell McKertrow, MB, Ch.B, of Red Roofs, Abbey Close, St. Andrews, Fife, and has issue, 1c • Alistair John DUFFUS, b 15 Nov. 1954, educ Glenalmond. 2c • Ronald DUFFUS, b 22 Jan. 1956, educ Glenalmond. 1c • Julia Frances Moira DUFFUS, b 10 March, 1948, educ Bedford Coll, Lond. Univ (BSc. 1969), m 26 July, 1969, • Dr. Michael John Parsley, BSc. [19, Chilberton Drive, South Mersstham, Redhill, Surrey], son of – Parsley, of Hove, Sussex. 2c • Fiona Ann, chartered Physiotherapist, b 13 Oct. 1949. 3c • Margaret Catherine DUFFUS, b 28 April, 1951, educ Lond. Univ 1b • Etta, b 7 Sept. 1916, educ St. Anne's Coll Oxford (MA. 1938), m 7 Dec. 1938, • Charles Francis William Rowley Gullick, BLitt., MA., Fell, sometime Senr Tutor and Vice-Prin. St. Edmund Hall, Oxford [Bincombe House, Over Stowey, Somerset], son of late Francis William Gullick, BC.L., MA., of Sunnymeade Cottage, Summertown, Oxford, and has issue, 1c • Charles John Montgomery Rowley [8/9, Parish Street, Mqabba, Malta G.C.], b 4 June, 1944, educ Magdalen Coll Sch, Oxford, and St. Edmund Hall, Oxford (BLitt. 1970), m 25 Jan. 1969, • Mary Isabel, eldest dau of Rev Arthur Brian Canning, MA., Vicar of Boughton Monchelsea, Kent. She m 2ndly, 1 May, 1952, Lt.-Col Tom Forster, T.D, late 74th Northumbrian Field Regt, RA, son of late Tom Forster, of Northumberland. He d 21 Aug. 1970.

The elder son, JAMES MONTAGUE COUTTS DUFFUS OF DALCLAVERHOUSE, purchased Claverhouse, and the Superiority of the lands, estate and feudal fief of Dalclaverhouse 1926, and additional lands 1934, Lieut. RFA (TA), matric. arms of DUFFUS OF DALCLAVERHOUSE, at Lyon Office 31 Aug. 1939, granted a Badge and Standard 16 Oct. 1944, b 18 March, 1891, educ Loretto, m 8 June, 1918, GERTRUDE (who s her husband in Dalclaverhouse, jointly with her elder son, and d 10 Oct. 1957), 2nd dau of Isaac John Collins, of Shaftesbury House, Dundee, Angus, and d 26 Nov. 1947, leaving issue,

1a • JAMES COUTTS, of whom we treat.

2a • John Coutts DUFFUS, FSA Scot, served in World War II 1942-46 with RA (Field), Town Cllr. Ballater 1963-66, Memb/memb Dean of Guild Court, matric arms at LO 17 July 1961; [Morrone, Cults, Aberdeenshire; Carlton Club, and Royal Overseas League], b 3 March, 1923, educ Arnhall Coll Sch, Dundee, and Coll of Agric., Aberdeen Univ, m 19 Dec. 1963, • Winifred Agnes, widow of Ian Lumsden, BSc., and yst dau of John Laidlaw, of Morrone, Cults, Aberdeenshire.

1a Helene Gertrude DUFFUS, Superior of the lands, estate and feudal fief of Dalclaverhouse from 1965, late W.RNS., b 7 Dec. 1926, m 1stly, 1 March, 1952 (m diss. by div. 1960), Hon Ralph Geoffrey Knyvet Mansfield, yr son of 4th Baron Sandhurst, O.BE (see BURKE’s PEERAGE & BARONETAGE 1999 Edn.), and d 1975, leaving issue, 1b • (Penelope) Sara Helene, b 1953, m 1983 • Dr. C.Neale Muir [Lot 16, Allen Road, Forestdale, Perth, West Australia]. 2b • Trude Charlotte Victoria, MP.S., b 15 April 1955, educ Univ of Wales Instit. of Science & Technology, Cardiff, m 4 June 1983, • Mark Timothy Borrett [Beckwith Farm, Lt Clacton Road, Gt. Holland, Essex C031 0ET], son of Norman Francis Borrett, and has issue, 1c • Alexandra Victoria, b 1984. 2c • Katherine Frances, b 1986. 3b • Tessa Emily Henrietta, b 1959, m 1981 • Steven Williams [16 Main Road, Middleton Cheney, Banbury, Oxon, OX17 2ND], and has issue, 1c • James Mathew Thomas, b 1995. She m 2ndly, 1 Nov. 1960 (m diss. by div. 1963), as his 2nd wife, Capt Ian Alistair Sinclair, yst son of John Alistair Sinclair, of The Mount of Glenuffin, Kirkcudbrightshire, and The Grove, Highgate, N.6. She m 3rdly, 31 March, 1969, as his 2nd wife, • Capt Raymond Stanley Lambden [c/o Barclays Bank Ltd., 137, Brompton Road, London S.W.3], only son of William Lambden, of Chobham, Surrey. Tartans–Day–Hunting McDuff and Clan Farquharson; Dress–McDuff (white). Address–c/o Royal Society of Arts, John Adam Street, W.C.2.

Duffus of Dalclaverhouse spending ends.

Here is a summary from above of the interesting Heraldic journey Coutts-Duffus had:

JAMES MONTAGUE COUTTS DUFFUS OF DALCLAVERHOUSE, purchased Claverhouse, and the Superiority of the lands, estate and feudal fief of Dalclaverhouse 1926, and additional lands 1934, Lieut. RFA (TA), matric. arms of DUFFUS OF DALCLAVERHOUSE, at Lyon Office 31 Aug. 1939, granted a Badge and Standard 16 Oct. 1944

His XYZ was JAMES DUFFUS, of Westport House, Cupar, Fife, JP, a Bailie and Dean of Guild of Cupar, b 23 Feb. 1822, m 19 Sept. 1848, Ann (d 2 Dec. 1904), yst dau of John Coutts, a Bailie of Cupar, of Bonnygate, Cupar, Fifeshire, and d 3 Dec. 1916, having had issue,

1a JAMES DUFFUS, of whom presently. 2a John Coutts DUFFUS,

James Montagues  xnd son was JAMES COUTTS-DUFFUS OF DALCLAVERHOUSE, holder in life rent of the superiority of the lands, estate and feudal fief of Dalclaverhouse (which he made over to his sister by Deed of Gift 1965) He assumed surname of COUTTS in addition to and before his patronymic 1946 {in more detail that meant he had a XYZ to chnage his name from James Coutts DUFFUS to James COUTTS-DUFFUS .ie, a hypheated name. Furtrhermore he the was granted arms.. twice?),

However in mmm he disconituned this use  and was recognised by Lord Lyon King of Arms in style of DUFFUS of DALCLAVERHOUSE and matric arms 6 March 1957