Still want to know what kind of plastic the keys uses, so would be awesome if someone could tell me.
Caps on my topre.

The keyboard I took the caps from.


And yes, that's birdshit on the keyboard, found it outside at work.
Some other pics of the caps and my topre:




And the caps are not yellow like it looks in the last pictures, it's just my lamp that makes a really yellowish light, took the pictures without the flash.