For my project I went with the individual ABM tuner bridges and it was appropriate to have a custom end piece made from plaster cast of the end of the broken neck, but dguitarparts.com was somewhere I had looked. If you don't need a custom option then that's where to shop!
Are the single tuner bridges on the dguitarparts.com site as well?? I'm not seeing them?? Also, what is the nut width of the ABM headpiece?? I'm going to convert a P parts bass I have here, I got the BUG