So I went rummaging around last night and came up with another option. I have a 350 carcass that I scavenged to rebuild mine. I would need a P&C and a bunch of miscellaneous small parts to get it going I think. It was a dished piston model (45mm). Would the carb (can't remember which model was on it, think was a zama?) properly fuel a standard 350 P&C? Looks like an OEM top end kit can be had for about $100. Or would I be further ahead to convert to 353? A snorty 346 may be a bit much for him yet.
I had been hanging onto it to cannibalize as needed, but it may just need to be rebuilt. Will have to further peruse my parts pile for it. Meanwhile, time for another look through the OPE classifieds!