I have seen a couple posts regarding the possibility of a Graphtec Floyd Rose on a JTV 59.
After much work and frustration I have successfully achieved the transplant.
Being that my main guitar is a Les Paul with a Floyd I found my JTV 59 not getting the playing time it deserved.
To be clear I DO NOT recommend attempting this transplant for the novice..... Without woodworking experience and the proper tools it can be a catastrophic failure. I have done many tremelo retrofits and a couple Variax transplants and even with that experience I was very hesitant to route away my $1500 guitar. One wrong route and it's game over.
The most frustrating part was the wiring, by adding the floating bridge and springs, the added noise caused the 12 string and alt tunings to pickup extra notes and be terribly wonky and warbly. At first I thought it may have been the bridge but after some rewiring and taming of the spring noise (by adding some foam in the trem cavity and under the piezo wires) it works great! With the graphtec nut and addition of Schaller locking tuners a locking nut is most likely not required.