A good customer brought his new-to-him Casino in for a little work.  We swapped out the tuners for Grover Sta-Tite open back tuners.  The mounting holes on the back lined up, but I had to play around with the bushings.  Normally with press-in bushing tuners, I keep the original bushing in the headstock and install the new tuners.  The issue was that the Grover tuner posts were a hair too large to fit the bushings.  So you would think that I could just swap out the original bushings for the Grover ones, right?  Nope.  The Grover bushings were too small to stay in the headstock so I had to remove the original bushings, ream out the inside diameter of the bushings and re-install.  Ah the joys of modding import guitars: replacing metric components with mis-matched imperial unit hardware.

The player was also having feedback issues with the full hollow / P90 design of the Casino.  An inexpensive fix was to stuff black foam inside the f-holes to help reduce the sensitivity of the body.  Oddly enough, the foam I used was from my stash of foam that Stewmac uses to package Waverly tuners.