I recently bought my first IBM Model M keyboard (1391401) on eBay. I noticed that on the bottom, there are two holes on the front side, near the front corners of the keyboard, that are empty. It looks like there used to be something in them that isn't there any more. It looks like I can see the steel backplate through the hole (see attached photo). The two plastic halves of the keyboard shell come apart a couple of millimeters if you stick you fingernail in the crack between them.
I am worried that the holes are for a fastener that isn't there, but it also seems to me that there would nothing through that hole to fasten to. Is the hole for a plastic anti-slip pad? If so, the loss is no big deal. I have looked at photos of the bottom of other Model M keyboards on eBay, and it looks like there is something in those holes. On two of the three photos I have looked at, it looks like a plastic anti-slip pad. In the other, they look like flat metal circles (a fastener, perhaps? Or just a dirty plastic anti-slip pad?).
Is the slight separation of the plastic halves no big deal? The keyboard seems to work just fine.
Any answers to the above two questions from people more familiar with Model Ms than I am would be appreciated!
