Shaun,
I'm not too concerned about the color, I just wanted something that was close to the right length and outer diameter, and that had some kind of knurling. The nuts that I ordered are black oxide, which is nice and understated on the instruments, but is still quite different than the original thumb nuts. I see on Amazon that similar "internal wrenching allen nuts" are available in stainless steel finish, which would be a much closer match to the original, but I haven't found 1/4-28 in stainless steel finish, and the prices on Amazon are absurd (or maybe that's just the quantities that are absurd).
I fully expect the brass inserts to work perfectly, but they will certainly stand out with respect to the rest of the instrument face. I've seen some "restored" oscilloscopes on-line where the BNC connectors have been replaced with gold plated ones. The brass inserts will look almost as silly.
I am frustrated, however, that I was not able to find exact replacements for the Tek binding post nuts. I found lots of diamond knurled thumb nuts, but most were too long, and/or their outer diameter was much too large. Most were also made of aluminum, which I am scared to have in direct contact with the steel binding post (maybe that fear is misplaced? The binding post is already in direct contact with the frame and face plate, both of which are make of aluminum in most, if not all Tek instruments).
I purchased a handful of NOS Tek binding posts with thumb nuts, of the smaller size for TM500 plug-ins, on eBay, and those should be enough for my use, but I haven't found any of the 3/8 inch length nuts commonly used on 500-series scopes and plug-ins.
-- Jeff Dutky
