Title page of the Marquess of Bute's, "The Roman Breviary"
However, quite by accident, I recently ran into this interesting bit of information on the diocesan website of Argyll which relates to this Catholic patron.
At the time of the restoration of the Scottish Hierarchy in 1878 the Marquis of Bute presented new mitres to the bishops of each of the six [sic] new dioceses - Galloway, Edinburgh, Dunkeld, Glasgow and Argyll.
The mitre of the Bishop of Argyll is pictured below...
Source: The Bute Mitre
It would be rather interesting to see photos of the other mitres as well if they are still extant, not only for reason of their beauty and craftsmanship, but also for reason of their tie to modern Catholic history.
For those interested, here is what the Catholic Encyclopedia tells us of the 3rd Marquess of Bute:
Born at Mountstuart, Bute, 12 September, 1847; d. at Dumfries House, Ayrshire, 9 October, 1900, was the only child of the second Marquess by his second wife, Lady Sophia Hastings, and succeeded to the family honours when only six months old. His mother died in 1859, and after some disputes between his guardians he was sent to Harrow and subsequently to Christ Church, Oxford. Here he came under the influence of the advanced section of the Anglican Church, whose tenets his keen and logical intellect quickly saw to be inconsistent with non-communion with the Catholic Church. Bute's letters to one of his very few intimate friends during his Oxford career show with what conscientious care he worked out the religious question for himself. On the 8th of December, 1868, he was received into the Church by Monsignor Capel at a convent in Southwark, and a little later was confirmed by Pius IX, in Rome. He was present in Rome during part of the sittings of the Vatican Council, travelled afterwards in the East, and then returned home to settle down on his extensive estates in Scotland and Wales.
In April, 1872, he married the Hon. Gwendolen Howard, eldest daughter of the first Lord Howard of Glossup, and had by her three sons and a daughter. A scholar and somewhat of a recluse by temperament, Bute had a high sense of public duty, and admirably fulfilled his functions as a great landowner and employer of labour. The first peer of modern times to undertake municipal office, he served both as Mayor of Cardiff and (twice) as Provost of Rothesay, in his titular island. His munificence was in proportion to his vast wealth (derived chiefly from his property in Cardiff), and innumerable poor Catholic missions throughout Britain, as well as private individuals, could testify to his lavish, though not indiscriminate generosity. A patron of learning throughout his career, he expended large sums in the assistance of impecunious scholars and in the publication of costly and erudite works. He was for several years Lord Rector of St. Andrews University, to which, as well as to Glasgow University, he was a munificent benefactor. Bute was a Knight of the Thistle, and also a Knight Grand Cross of St. Gregory and of the Holy Sepulchre. His personal habits were simple; but as a lover of art, with means to gratify his taste, he surrounded himself in his various splendid homes with much that was artistic and beautiful. His last years were clouded by a long and trying illness, patiently borne; and he died as he had lived, a devout and humble Catholic, a few weeks after his fifty-third birthday.