Greetings my good Doug
If my little grey cells are working properly, I seemto recall that the factory initially offered ony the 7 1/2 inch, thn later the 5 1/2.
However, they were happy to make any length by special order.
As a result, the documentation with which I am familiar for the 4 3/4 ( or 4 5/8 or whatever) is contained in the Letter from Bat Masterston to Colt's requesting an SAA with a barrel "about as long as the ejector"
"On July 24, 1885 Bat placed an order with Colt’s for two revolvers, completed for shipping on July 30, 1885. "
ahhh, here we are:
http://gunsoftheoldwest.com/2013/02/bat-mastersons-colt-saa/2/"During the course of his career as a lawman and gambler, Bat ordered a total of eight single-action revolvers from Colt’s. The most notable was an order made from Dodge City and written on Opera House Saloon stationary in July 1885 which stated,
Gents
Please send Me one of your nickel plated short .45 calibre revolvers. It is for my own use and for that reason I would like to have a little Extra pains taken with it. I am willing to pay Extra for Extra work. Make it very Easy on the trigger and have the front Sight a little higher and thicker than the ordinary pistol of this Kind. Put on a gutta percha handle and send it as soon as possible, have the barrel about the same length that the ejector rod is.
Truly Yours,
W B Masterson
P.S. Duplicate the above order by sending 2"hope this helps
prof marvel