Had 2 Y 18+ prox's fall off the 2 Desktop's AND relocated my Y 4 times trying to maximize(should have left it alone).
Shopbot said scrape and clean/Gel super glue back on.
IF you can "Feel" a definite spot where it seats, maybe just add a drop and spread it?
If you have to razor blade clean it, maybe a sharpie mark to help re-align?
It will now rezero to new location, so any spoilboard references may be off.
Probably get better advice for full size machine if you wait a bit, but Desktop prox are still fine with gel and it's been a year. Denatured beforehand.
scott P.
2013 Desktop/spindle/VCP 11.5**
Maine