Nashville/ABR Conversion Surprise
I put a Tonepros AVR1 on my '78 LPC. It fit, stiffly over the stock posts. After, you know, paying attention, I realized the stock bridge was a Nashville, and the AVR is intended to be a ABR style, and really shouldn't have fit at all. I ordered a conversion stud set from Guitarfetish.com (basically, ABR posts with threaded bushings), figuring that would sort it out. The new bushings fit right into the existing holes in the top, no problemo. The new, ABR-sized posts fit right into either bridge, and a micrometer confirmed they were the same size (0.162"). I chalked up the stickyness of the old posts to three decades of accumulated muck and corrosion.
That, however, does not explain why the posts were not Nashville sized. Was there an intermediate bridge? Was there an aftermarket part that meets the description, ie. wider intonation range, ABR posts and Nashville threaded stock?