Oh yeah I'm getting a vintage M! Mark my words ander, I will get one. Too bad they don't show up at all where I'm at and there's no way I'm doin' eBay right now. But my birthday's here in about two months so...
Good for you, dude. And don't get me wrong—in no way will an original Model M detract from your enjoyment of your Ultra Classic, or vice versa. Once you can experience them side-by-side, you'll understand how each one has its own charms and personality.
If you want the absolutely most solid, 1st-gen Model M experience, hold out for a part no.
1390131 or
1390120. They were made from around 1986–88, and are the earliest two Model M versions that are PC-compatible. Some have the early Model F-type "barcode" labels (I've pointed to the part numbers):
...and later ones have simpler labels:
'120s are a bit cheaper and easier to find than '131s because they don't have LED status lights:
(They were made for terminal-emulation programs where Caps Lock, etc. was shown onscreen—but most of us can tell when our Caps Lock is on without little lights to tell us, LOL.) That's the only difference between them.
Otherwise, look for a no. 1391401 (the most common Model M number) and get one with a gray logo in the corner—rather than one with the newer blue logo—so it'll be that much different from the board you already have.
You'll also probably want an electronic converter to switch the PS/2 plug to USB. I've found that the best type are these keyboard+mouse cable-style converters:
You don't have to use the mouse connector. They're just a couple of bucks on eBay, including shipping.
Assuming your M is used, you'll want to clean it up before you use it. Here's the basic procedure:
1. Use a key-puller tool:
...to pop off your keys. DON'T risk breaking your precious vintage keys by using a screwdriver or some other object. If you don't have a key-puller, they're quite cheap online too.
2. Separate the caps and stems. The stems are usually covered and rarely need cleaning, so just set them aside.
3. Soak the caps (and any one-piece keys that don't have caps) in warm water with some liquid laundry detergent, for about 30 minutes, stirring them every 10 minutes.
4. Rinse the caps well, then let them dry
overnight to be sure every bit of moisture is gone before you put them back on.
5. While your caps are drying, wipe down the case with some alcohol on a rag or paper towel. (It won't hurt IBM's sturdy case material.) If there's dust or other debris on the key bed, you can wipe that out too; Q-Tips are useful for getting into the small places.
You probably won't have to open the back of the case (which requires a special 5mm hex wrench from an electronics store). As long as the board works OK—and they usually do—don't worry if you hear a bit of rattling inside; it'll just be a few of the plastic rivets that have come loose after 20+ years of service. It takes quite a few of them coming off to make any difference.
Well, sorry if I've overwhelmed you with stuff you may have already known. (I live in the suburbs, though, and it takes extra effort to feel useful out here, LOL.) And if you have questions about anything, feel free to ask!
Just imagine me walking into a Goodwill and there's an SSK... the day after I got a new-used M. xD
I'm imagining what could happen already. Been there, done that.
As you can probably tell, Snow has been everywhere and done everything—and yet he still manages to be enthusiastic now and then. :?)