I've just fitted a pair of Schaller s-locks on a Tele, which was so simple I wish I'd bought a set when I bought the guitar; fitting the strap is so much simpler now. From case to ready to play is much faster than faffing around fitting the strap and then rubber rings to make sure it stays on.

I also have a Gretsch G5420T which has screw on strap buttons. When they're removed there is what looks like a bolt protruding from the body. Does anyone know if this can be unscrewed from the guitar? Is so, I can remove these and fit Schallers, but I have concerns that trying to unscrew the existing fittings could cause them to break off altogether.

The only information I've been able to find states they will fit the same thread, which is nonsense as Schallers fit into the body like a screw.