It's too bad you can't play before you pay, but can an RB era snares really be that bad? Surely not all of them sound boxy. There are a lot of variables, head combinations, snare wires, tuning etc. Modern heads can be fitted better with wax.
One of the most experienced drum collectors I know says they can never be great. I think the best vintage wood shell snare is a Rogers Powertone. Not cheap, but sound beautiful and work perfectly. Just a great simple snare that kicks butt.