the 3xAA Mini Mag is pretty rare as far as I know. Although obviously 3xAA's makes it long too.
The best/easiest upgrade is probably a Match p60 upgrade. Running the light on 3xLithium (1.5v) or 3xEneloop NiMh (1.2v) would give you a lot of choices.
But doing this mod will cause irreversible damage to the light.
It really is an easy mod to do.
The only thing to check is if the head is different, as latter LED MiniMags certainly used a different head to the incan ones. Not sure it's matter either way, but the dimensions are slightly different.