I have a les paul that has a set of grover tuners. Is there a way to tell if it originally had klusons? There are currently no extra holes that can be seen on the headstock.
If it didn't come stock with Grovers, you'd be able to see an extra hole over each tuner. Grovers have a set screw underneath each post, Klusons have one on top and bottom...
Traditional Klusons:
Grover Rotomatics:
So, after the switch from Klusons to Grovers, you get this: