
I'm seeking out help for a small but significant problem with my Model M (a 1393395, if that matters). I started using it with no problems at all; I also, in some occasions, removed the keycaps (both parts) for cleaning and replacement. After some time - at least two months - I started noticing that the right Shift (a peg-stabilized key) binds quite a lot when pressed on the right extremity. It's not that annoying, but I definitely feel it, especially when hitting Shift+Canc or Shift+Ins.
This effect does not go away if I remove and re-insert the keycaps - which is, by the way, the one te keyboard came with. And the stranger thing is that the right side is the side of the switch, while the stabilizing peg is at the left.
Now, the problem is that I'm not entirelly sure if the key did it the whole time or if it started at some point. And I don't have any idea of what the cause could be. I was about to decide it had to be there from the beginning (even though it's macroscopical and easy to notice), but then I acquired another Model M (albeit a later terminal one) and the right Shift works perfectly.
I'd like to solve this problem but, as I explained, I don't know how to find the cause. What can I do?