I picked up an Apple II SCSI Card off of eBay, sold "untested." It was cheap, and the photos made it look to be in good shape.

It has exactly one electrolytic capacitor, and it didn't look to be leaking but I was still wary. After desoldering it, it tested fine, but I already had a replacement in hand.

I tried it in my Apple #IIgs, with my external #BlueSCSIv2. There were no fireworks, but it didn't want to boot off of the drive image: "UNABLE TO LOAD PRODOS". I'll poke at it again soon.