I didn't respond at all because I wasn't sure what you were talking about.
Do you happen to have any photos?
If I'm understanding you, the brass bottom plate that the mounting screw
and spring attach to is broken off?
Ouch. I'm sure it's repairable, but it might take some work.
If you're handy, you might try sanding the brass back plate flat, and
soldering on (copper water pipe solder, not electronics solder) another
brass plate right over the existing one. You would have to then redrill and
retap the mounting holes, and mabey the holes for the six pole pieces
if they are the kind that extend through the brass base.
If you do replace it, I could use your old pickup for parts. Drop me an
E-mail at [email protected]