while digging through a box of spare parts I found a couple of steel frames for colt copys. most of the parts are Pieta. One is a 51 navy and the other is a 60 or 62 . both are 36 cal. Id like to build a short barrel version . If I was to find a brass framed Pieta pistol would the internal parts fit the steel frame?brass framed pistols seem to pop up for sale cheeply much more often. thanks in advance DR.