I have an image of the platen area, but don't see any way to post it, unless I have pic on a URL - but I don't know how to do that.

Thanks

You're probably going to be looking for a few grub screws holding the platen knobs and the platen itself to the spindle. The platen usually has two screws per-side, set 90 degrees from each other. The knobs may have one or they may simply unscrew, I'm not sure about this model. Most likely grub screws or even more uncommon a locknut.
You'll remove the spindle and lift the platen straight out.
I'm only starting out in typewriter repair and there are plenty on this forum that have way more experience then I do, so to them I'll defer. Just make sure to use good screwdrivers that are properly sized.
If you're not loading paper right, you probably have flat spots on the roller. Your machine needs more cleaning if keys are still sticking.  You can gently stick a hobby knife into each slot of the segment and pull out the old stuff in there, then flush it with mineral spirits or naptha. Watch that old lacquer paint and don't get any solvents on it. Don't lube the segment slots but lube the entire linkage all the way back to the bars which connect the keys. Use a very light synthetic oil like liquid bearings, or maybe some dry product like 3 in 1 lock lube used for door locks. It sprays on then dries and doesn't leave a sticky residue. Make sure your key bars aren't touching the sides of any combs as that will cause them to drag.
You can paste image URLs directly into threads while you build up enough posts to have them inserted into threads directly as images.

Phil Forrest