EDIT: I've updated this thread with my results so scroll down if you're interested.
I recently purchased a very nice first generation C-Record rear derailleur and while installing it noticed the cable anchor bolt hole is stripped. Here are a few photos for reference. First photo is with the M5 (5mm) bolt and cable plate installed, second photo is without the plate and bolt, third photo is just for location reference.
So I know most of you will suggest I drill out the hole and re-tap to the next largest size (M6) and there is certainly enough material around the hole to do so. However the hex head of an M6 bolt is considerably larger, and would be an eyesore on this rare classic derailleur. Perhaps I could get a nice chrome one. I've already searched for an allen head screw and a machine screw that would be less offensive, but have had no luck. I also would have to enlarge the hole on the small steel cable plate, and that seems like it would be a pain.
I'm wondering if anyone has had experience with a Heli-Coil thread repair kit for a hole this small. I found one kit online here: http://www.sjdiscounttools.com/hel5546-5.html
The heli coil threads are a little long. Can they be trimmed to fit shallower holes? Also, I'm open to any suggestions or input anyone can offer. Should I forget the heli-coil and thread and re-tap? I've heard thread repair kits can be stronger than the original hole. Whadaya think?