There are plenty of RBs out there in great shape. Those are the closet cleanouts of old pros converting to digital. Most are in need of some service but minor almost DIY type stuff like replacing foam seals. The one thing you must be aware of are the lenses. They don't store as well when not being used.
Lenses are always in more need of service than the bodies if left unused. They tend to get slugish, the lube cakes up. The good news on older shutter is they were made of top quality brass n were beautiful clock works compared to the newer varieties that have cost saving stamped steel n plastic parts. I love working on the older shutters because they leave lots of room for adjustments n don't seem to die as easily as the new ones. The modern versions are disposables, no parts available anymore either... shame, they do have nice glass.