I have serviced quite a few F's.
First of all you have an XT there , the plate is a pain the the ass to get on as the PCB for the controller is in the way only open it if you 100% have to. The rule with F foam is , if it feels and works ok then leave it alone.
If you have to open it be careful, you do not want to break any of the tabs , it is fixable but its a pain in the arse. to put it back together you will want a rubber mallet or plastic deadblow hammer and some clamps ( or very strong hands), the XT is the hardest one to get back together in my experience.
A top tip, you can use a bulldog clip to replace a broken tab , you just have to get the right size , not sure what size i used just order several smalls ones, you put it on and then take the sliver leavers off and leave it on there , and then you can use the leavers as keycap pullers
Some caps looks like they have stickers on, its very strange, i had an XT with almost identical stickers on the same keys.
The XT case is painted and very brittle, be super careful around the thin bars that separate the F keys and the main body. If you want to paint it you could build up the texture in the damaged parts with high build primer , just dab it on with a cocktail stick, then plastic primer and then paint. RAL 7030 is what you are looking for if you want industrial grey , its the closest.
If you need to repair barrels , remember the XT is the black sheep and has a different design of barrel than a AT 122 4404 etc , they have the pin type rather than the keyed type, you can use the pined ones on the new keyed type by snipping the pin off but i have never tried it the other way around, if you need replacement barrels make sure you get the XT type. You may well be able to snip off the keyed part of the barrel but i have never tried this .
There are several different flipper types for model F but they have no noticeable difference between them. Springs as far as i am aware have never changed.
I have some very limited spare parts for all F's so if your stuck let me know.