I took my original non-working 67 tach and just had it completely redone with new guts by Redline Gauge Works . They restored and repainted the face and replaced all of the old insides with modern equipment. Thing looks 100% original but should work like brand new (its been tested, but I have not put it on my car yet). It hooks directly up to my HEI as well. It wasn't cheap as was around $400, but figured I would pay the extra and have my original tach working instead of paying $200 for a cheap knock-off.

Only problem is the original is also a single bulb and is dim, but I am looking to replace the standard bulb with a brighter LED and see how that works.