Revolver No. 1(topmost) is the most accurate looking to me. However, you say it is .40 caliber, which means it would not be a copy of a Colt Navy. Nor would it be a copy of a Dragoon, which would have had round barrels.
I'm sorry I can't be of more help, but the guns appear to have been so modified over the years as to no longer be recognized as to their original form. The top gun has had its barrel shortened at some time, as there is not latch for the rammer.
When, and if, you do restore these guns, what are you intending to do with them?