Looks like a 2nd Model MKII originally made for the Brits for WWI. Has been refinished and doesn't have the correct stocks. Would originally have been in .455 caliber and was converted to .45 (45 Colt or 45 ACP isn't obvious from the caliber marking) but you can try loading a 45 Colt round. Nice old guns but in that condition not worth a whole lot, maybe $500. As a family pass down though it may be very valuable to you especially if you knew that uncle very well. Enjoy it and welcome to the Forum. There is a research thread, maybe can find by putting ".455 research" or something comparable in the search option at the top of the page. That thread, and others, have a great deal of information about these revolvers.

Jeff
SWCA #1457