OK, this is not a tool for guitar work purposes, but it is important information I want to pass along to the readers and customers of this website
Do not buy original equipment manufacture (OEM) Harmony tuners.
The image below shows one of two versions of these tuners. The older version has brass gears. This version has steel gears. Both versions have screws painted with gun metal blacking as a rust preventative.
Theses tuners are pure junk, even when brand new never used. I discard these and will not sell them to anyone because I consider selling these tuners a rip-off.
Original Harmony tuners were very poorly made and cannot be repaired. The gears are incorrectly cut causing excessively difficult tuning. You can detect this buy turning the grips. You will notice a spot in the turning that becomes harder to turn. This indicates a bad gear.
The Golden Age Restoration tuners sold by Stewmac are much better. However, the best "budget" tuner for guitar restoration is the Grover Sta-tite. Unfortunately, these have metal grips so they don’t look as vintage as the Golden Age Tuners, but for the money the Grovers are top notch and a great value. You will notice the improvement immediately.
One caution: improved tuners require solid metal bushings. Installation requires a drill press. See elsewhere in this website for installation instructions.
©2021 D.R. Hanna.