I always liked these types of pistols in .45 cal. over the .50 cal. pistols. I had several in .45 cal that burned with the house. For some reason (to me) .45 calibers felt a little more authentic than .50 calibers. I may be wrong, but that's how I felt when shooting them.
I've owned a number of these guns in both 45 and in 50. Fun shooting. I really regret selling the two I had in .45 cal....one had adjustable sights added to it and was very accurate.
Those of yours in the picture bring back memories.