Got a reply from Grover.. Apparently none. Specs on these 50 year old things are completely different to modern tuners.
Need to find replacement. Oh joy.
Anyone knows what kidneybean knobs AND Screw i can get for these Futura tuners that fit?
Restoring a Greco 78, and these was on it. Still works ok, just need a new kidneybean and two screws. (One had a broken screw too)