My Frankenbow (a set of Samick Sage limbs bolted and epoxied, in a way, to the magnesium riser of a Bear LTD compound) is top heavy...it wants to fall over when held loosely at arms length.  Every other recurve I've had  balanced well when suspended in the base of the grip, but this riser  wasn't meant to be a recurve..it was the support structure for a complicated set of multiple brackets, pulleys and cables.. and its top-heavy. A stabilizer in the bushing would probably "fix" that, but I don't want to haul a stabilizer into the woods, etc.  I first want to get it balanced "naked" . Theoretically, I can drill out some of the mass in the riser above the grip, but I don't want to start drilling unless I'm pretty certain I'm on the right track, as I cant put back what I drill out. The bow is already rather heavy, so removing weight sounds better than adding more below the grip. Thoughts? Suggestions?

I had a friend machine slots in my riser. I've been shooting it for years with limbs up to 55#
 

I think your idea is going to be the winner, Ben. It's definitely a manufacturing defect...I bought another RH riser from a TradGang member and this RH riser is perfectly balanced and weighs noticeably less than my lefty riser.