10 pin or 12 pin refers to the diameter of the "crank hole" the pin that holds the piston onto the crank goes there. It really isn't anything you need to worry about, nor the brand of anything at this point, unless you are deciding to part it out. Why are you so worried about the wiring if it has spark? Attach that shit where ever you want, it doesn't matter, as long as there's spark its a non-issue.
If its an air leak you are going to need to rebuild the bottom end and put in new top end gaskets, get a Vespa rebuild kit from treats, 1977 mopeds, or zippy mopeds. I believe there's a tutorial in the wiki. The engine uses paper gaskets so take all that silicone shit off. Who knows, the dumb fuck before you might not have ever done this when he put the kit on, so you should do it anyway for a non-runner. While your at it take off the carb and find out what jet is in there he probably just left the one it came with in there.