Contact VML at
"IAN ST.JOHN-WHITE"
They do a repair service with a hardened helicoil thread, a ballbearing and a spring worked through a hex grubscrew from the back. You apply pressure by using an allen key and it wont ever happen again. I had mine done years ago - it was about £35 then only problem is you have to dismantle the trem and send the block and arm off to them - takes about a week
Bob the Builder, February 2005