Howdy
I don't quite understand when you say the 'pin' that holds the firing pin in place was too loose. The firign pin is held in place by a rivet that goes through the hammer and fastens the firing pin in place. It either holds the firing pin in place, or it doesn't.
If I was you I would call up VTI gunparts and explain the problem to them. Hopefully they can fix you up with the correct firing pin for your particular revolver. There may have been different firing pins available over the years. You can reach VTI gunparts here:
http://www.vtigunparts.com/Incidentally, a firing pin should protrude a minimum of .045 through the recoil shield and a maximum of .056. You can lay a drill bit on the frame to get a reasonable idea of how much your firing pin is protruding.
Regarding your cylinder, check for a raised burr around the hole in the frame where the firing pin is. It is very common with Italian replicas for the firing pin to raise a burr. Some say it is from excessive dry firign, but I have experienced this and I never dry fire revolvers. A raised burr can interfere with the heads of cases in the chambers as the cylinder turns. Colts have a hardened insert pressed into the frame to prevent this from happening, but the Italian replicas do not. Every time the firing pin falls, it drags a little bit of metal from the frame through and eventually can raise a burr. You can remove the burr very carefully with a sharp file, by carefully laying the file flat on the recoil shield and carefully drawing it across the frame. It should only take a few very careful strokes.