As we all know, sometimes you walk away with a real gem from eBay auctions, while at other times you end up with a pig in a poke. I fell victim to the latter when I bought a silver-label M-122 from a seller who advertised having multiple boards in the same great condition but only bothered to photograph one of them. I regret not taking any "before" photos, but the original case had a number of flaws including deep cuts which looked like they were put there with a knife and areas in which the plastic had been worn smooth from many years of hard use. I had actually tossed the case in the garbage at one point but fished it back out when I decided to do a full restoration.
Most of us got bored long ago with the IBM beige color scheme, but one thing you have to admit is that it is tasteful. They obviously put some thought into the pearl-and-pebble combination, compared to the tacky gray-and-black combination that Unicomp came up with on their own. Since I knew I wouldn't be able to find keycaps as nice as IBM originals, I decided to work within the existing color scheme.
This is what I came up with. The color is called Satin Fossil, and, depending on the light source and angle, it appears gray, green or taupe.
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You can see that it works very well with the pebble keys.
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I've found that there is a bit of variation in hue, sheen and legend quality even among genuine IBM caps, so I selected a set from my inventory that had the sharpest, blackest legends and the most uniform hue.
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Due to the imperfections in the original case, I had to sand the entire surface totally smooth and then recreate the texture using the appropriate (satin) paint. I applied four coats, with 7 days' drying time and light sanding between coats two and three. I think the surface texture came out pretty nice.
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While I was at it, i modernized the layout a bit.
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The feet are a contrasting Matte Deep Forest Green. Pro tip for anyone painting the feet: mask off any areas that aren't visible with the feet extended as any paint on the internal areas will cause the retraction mechanism to bind.
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As with most of my old IBM boards, I've fitted a Soarer's converter and custom Techflex "rattlesnake" USB cable.
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Internally, there were a total of 23 popped rivets. I've sourced these delightful hex pan head screws locally, which are low enough in profile to even use on the front row.
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What I've found is that the early Model Ms appear to be better made than the later Lexmark and Unicomp boards. For one thing, the steel backplate is thicker. To me, a properly bolt-modded, early M is almost as nice to type on as an F.
Not wanting to damage anything visible, I used a small end mill chucked in a rotary tool to make a hole in the plastic behind the badge, then pressed the badge out from the rear. 
