May I suggest putting some penetrating oil to loosen it up a bit? PB Blaster or WD-40 will do just fine (please do not spray these things in the mechanism, otherwise it'll gum up and you will have a small disaster on your hands)

ztyper wrote:

Hmmm. Looks like the right side lifts out because the lack of a solid piece keeping it in place. As for the right side... I think there might be some set screws that release the rod through the middle of the platen. I'm not sure how it works, for I have a 1940 Underwood Noiseless, which is about a difference of 10 years compared to yours. Try putting the left platen knob on, then pulling out the rod. It's hard to get a platen rod out with no knobs 

I've been able to find one screw on the left side of the platen rod, thugh the rod does not seem to be willing to submit very easily. If it helps identifying the mechanism, I've noticed that when I pull on the left knob it releases the ratchet allowing the platen to spin freely. It pulls out to the ratchet release point but duesn't want to go any further. I think I'll try lubricating the right side and gently persuading it with a hammer, as suggested.

TypewriterGuy wrote:

WD 40 will gunk up things, PB Blaster is a little bit better, because its naphtha.

Noted.

I've found WD-40 satisfactory for freeing up stuck bolts and things that refuse to move. What you DON'T use it for, is for freeing up the mechanism and the segment. That will gum it up like there's no tomorrow. (Personally I prefer PB Blaster anyways)

So, not wanting to take any risks here I bought some white spirits to clean it as many in the "typosphere" have recommended it. I also got some compressed air which made quick work of the dust and cobwebs. Next I'll try to loosen up the right-hand platen fixture thingy with the spirits and some gun oil maybe. Would the spirits be safe to use on the glass keys aswell or should I keep clear of that?