Well, I will disagree a little bit. Reason being that I HATE the Pietta base pin, with them being only notched on one side instead of having the groove go all the way around the pin. PITA at times to get it inserted perfectly. The Uberti Lightning and Model P Jr (Stallion) have the same type of pin, which I also hate. If I had a Pietta, I would probably replace it with an Uberti pin (and cut THAT one short).
Medic15al, if you do plan on using a Colt base pin, you might want to do some measuring first. I have heard of people using a Colt pin in an Uberti, and I have stuck an Uberti pin in a Pietta just to see if it fit (it did), but one poster on this site (I think) some time in the past year stated that a Colt pin would not fit his Pietta. FWIW.