Hey there, BegD !
With thin-ply re-ring shells, you can "train" 'em back a little bit. A "forgiving" reso isn't the answer, though. Discipline is.
First make sure the hoop is round. That, in itself, will help coax the shell a bit toward behaving more roundly.
Use whatever type of reso you normally would. As long as you can get it onto the shell without a hammer, seat as best you can, put the hoop back on, and tighten her a little more than you normally would.
Place the drum on a carpeted floor, take off your shoe, and step onto the center of the head once or twice. Believe me, the head and the shell can easily withstand it.
That will fully seat the head, and possibly begin the discipline of coaxing the shell back a bit toward roundness. And if none of that works, well, hunt down another one on eBay, then put the out-of-round one to rest.
Hope that helps.
:2Cents: