I recently had my Tachometer take the shits and ordered a rebuilt one from Bobby Carter in Portland Oregon.
He can rebuild any Magnetic Smith's Gauge from 1964 to 1976 to be as good as new. His is very reasonable and has a quick turn around. He will trade work for gauges if you have any laying around or purchase them outright, even if they have been damaged he would still be interested for the right price.
Bobby's number is 971-998-3530, give him a call he will get you taken care of, no need to be a DIY and mess around to getting it right.
This is the work detailed on the rebuilds... The internal parts of this gauge have been removed, completely renovated and calibrated to meet the specifications of a newly remanufactured gauge. The rebuild of this Smiths gauge included the following: The can (case) was professionally powdercoated to Concours quality standards. The can does not have a single ding, dent or damage. Then the inside of the can was painted with white epoxy paint (the only paint that will not peel, turn to dust) for many, many years. Then the blue, light enhancing, paint was sprayed on the one section of the inside the EXACT same way and in exactly the same shade as Smiths did it when this gauge was built. This gives a softer shine to the light rather than just harsh white light. The correct shade of bright white was added to the needle’s arms. Then a NEW bezel, glass, upper and lower rubber glass sealing seals, new stainless steel chassis screws (will never rust or tarnish), the internal and external shock absorbing rubber biscuit mounts and the stainless steel nuts and washers (for the mounting of this gauge to the stock NORTON barrel bracket) were added. This NORTON gauge is ready to JUST BOLT ON AND GO...
Paul