Steve the bits that the allen bolts screw into are a steel rivnut, I use alloy rivnuts for some of the bike mods I have done.
If you do end up destroying them all is not lost. I usually get spare ones from Trident supplies at Silverstone two doors away from Fonza Italia.
the tool I use is a Laser one, not that well suited to the steel Rivnuts
http://www.lasertools.co.uk/pages/tr...s.asp?type=Nut http://www.lasertools.co.uk/home.htm Or the cheap way
http://ourworld.compuserve.com/homep...ng_rivnuts.htm