What clan!!!

[SteveB]

The manner of dress and pose is something that was popular in the 1860's on this side of the ocean. American fascination with the feather and cap has nothing to do with being a chief. It was worn by the groom at a wedding here as a symbol of heading his own family.
As far as spelling and writing goes. All one needs to do is sit down with the registers of birth, marriage and death records at the state archives for about two hours and realize that the standardization of spelling for official records and penmanship were a severe challenge until the typewriter came into common use for record keeping. Here in Massachusetts I spend many hours pouring over the 1841 to 1910 registers to find that spelling started to become "standard" about 1890 and penmanship was never the same from year to year. On many an occasion a persons name changed spelling with every event. Born McNeilly, married as MacNeily, died as McNeally. Gravestone reads MacNeilly. All for the same person, just many different clerks, and the gent did not read or write, as the clerk had to note his "mark". I won't even go into the butcher job that my German great-grandmother's name went through (she did not speak English).
There is a problem with the first letter being written as a Palmer method "Q".
a first impression was Jenkins / Kristie or Rustie 65. It would help if there is any other items that came with the photo, such as the photographer's name or studio. and the signature of the colour artist. If this was in a frame, what kind of frame? The colours that appear in the gents "tartan" do not seem to come up with a tartan name easily in the Tartans Authority database. There are many close but nothing that is a dead on match.
Good luck with identifying this couple.

[BoldHighlander]

On many an occasion a persons name changed spelling with every event. Born McNeilly, married as MacNeily, died as McNeally. Gravestone reads MacNeilly. All for the same person, just many different clerks, and the gent did not read or write, as the clerk had to note his "mark". I won't even go into the butcher job that my German great-grandmother's name went through (she did not speak English).

I can relate Steve. One of my own ancestors came to this country in 1740 with his named spelled as Scoby. By late 1700's in Kentucky, land records have it as Scobie. By the census of 1800 (more or less) it was Scobee. Incidentally, his two sons who lived nearby had their name spelled as Scobie on the same census!

[O'Callaghan]

I don't have an opinion on what the inscription says, but I think that spelling was more uniform (and literacy higher) in the old world than the new, at least at that time. Hence, Rathdown is probably right if he were talking about Scotland, but not so much concerning the USA. He does raise another important point, though, that literacy was better in the cities, although in the modern day probably the opposite is true.