I collect and refurbish Model Ms for myself. My collection includes an industrial (1394946) and many (many) 1391401s. This one, however, may be the most interesting Model M I've acquired.
After being highlighted by ElecPlus, the board wound up on eBay, where I acquired it from XMIT (can't saying enough good things about XMIT and his auctions, when he has them). My original intention was to use it as a parts donor for other projects, and it did indeed donate its barrel plate, back plate and (remaining) keycaps. But, when I was going through a box of Model M stuff earlier today, I happened upon the case and said, wow, this would be an interesting project. It was also a good excuse to use a spare, generic 1987 IBM Model M controller I had sitting around.
Here is the board as photographed by ElecPlus (pic #1) and XMIT (pics #2-3):
And here it is as I added a like-new backplate (pulled from a 1990s Lexmark RJ45 Model M) and cleaned the board up. The original membranes were toast, so I added a set of Lexmark membranes from a different mid-'90s RJ45 Model M. Perfectly compatible with the 1987 controller.
The case and replacement membranes were filthy. I store all this stuff in a storage unit that also has gardening supplies (I do commercial landscaping on the side), and a bag of soil had gotten spilled on top of the case and replacement membranes. Both halves of the case, and the membranes, went into the kitchen sink with Dawn soap and an old toothbrush. I didn't think to photograph any of that, but you can see the effects of the soil on the top case (upper right-hand corner) where the color is now yellowing.
With the "new" keycaps, this is essentially a 1988-cased 1390120. I don't mind the lack of LEDs at all. The weight is 2,061 grams or 4.54 lbs (without the cord), which is identical to the weight of my industrial Model M (which hasn't been bolt- or screw-modded, and also without the cord).
(Note: You can right-click and select "open in new tab" to see the full-size images.)
Back label today just before I started the project:
Drilled and washed a 1986 barrel plate, and now getting the assembly screwed together:
No rust on the backplate!
Engraving on the backplate:
Installing the "new" keyset:
The whole project so far. Still need to wash the top case.
The controller, originally from a 1987 1391401 (the keyboard will be compatible with removable SDL cords):
The case has been washed. Now, testing all the springs/keys (going by feel) and adjusting tension on the screws before I insert the final 10 or so screws and assemble the case:
Finished project:
Using it to type this post:
A few days later, after some further external case cleaning:
I also replaced some of the number keys on the right to get a set of better-matching sublegends.
This keyboard is special to me. How many of these, especially this part number, have been lost to the ravages of time? Thanks to the efforts of ElecPlus, XMIT and resellers like them, these keyboards have a second chance. It types pretty well (feels good!) and will be my daily driver for the next few weeks.