I never thought a tool thread would be unpopular! I guess upthread is probably on the money - not many RBers will be paying their LBS to restore their bikes.
I do nearly all my own spannering (except stuck seat posts, can't be arsed!); and I'm getting the hang of restoring paint/dents/bends quite well. I've recently learned low temp brazing and can sort most problems and fit accessories to my frames. Two things I know next to nothing about though are carbon repair and titanium.
It never occurred to me to restore old tools though, but it's a good idea, especially when new stuff is so absolutely shite! I have a nice collection of VAR tools going back to the early 20th century. Repairing tools, with other tools could be quite an interesting thread.
I never get bored of using or buying/tuning new/used tools. My project for this summer is to build my own wheel truing jig, and do away with the shit I've been using all these years. I wonder how many people have access to CNC/routers/milling machines though? I can get access to almost anything, including laser cutting/3D metal and plastic printing at work, but I'm not sure it would be of much interest here?
Zero Gs thread on carbon repair was very interesting. I wouldn't try it myself (I only have one carbon bike and when that dies, I'm done), but it doesn't look beyond the skills of most people with a little light engineering knowledge.
