Q: Why did I buy a refurb floppy drive?
A: Because I still consider myself new to the hobby and wanted to get my A500 working in stock form before adding non-period hardware into the mix.
The drive I received appears to be a PC drive that was modified to work with Amiga. The internal connectors were switched around. Fortunately the power and data cables reached OK. The eject button did not line up with the case hole. I scrounged a spacer in my junk drawer and got that sorted. Several disks don't read in the refurb drive that work just fine in my A1000. The money was not a total waste because I got the machine into Workbench a few times and the times I did boot a game it worked OK. I consider the motherboard now fully validated.
Next step:
I've read some games insist on being in df0. That means replacing the 1.3 ROMS and using the boot menu won't achieve what I want. If I read the description of the ACA500+ correctly, that device has the ability to force an external drive to be seen as df0 and solve my problem for those times when I want to boot from floppy. That expense will have to wait. It's time to tear the A500 apart for a good case scrubbing and repair the rust on the RF shield.