90sCro-MoFan
Dirt Disciple
I used a Teflon grease (Bikehut brand from Halfords) when I rebuilt my Quadra 21s. Invest in a good set of extractors (sometimes called "easyouts"). They're made from extremely hard steel, are tapered and left-hand threaded. You drill a suitably sized pilot hole in the head of the offending bolt, or screw, then wind in the extractor which, being tapered will eventually get a good grip and at the point when the extractor won't go in any further, the bolt should begin to unscrew. I had to use one when I stripped my Q21s down. One of the bridge mounting allen bolts had rounded off and was impossible to get to with the old faithful molegrips.