"for some reason I can't find a tool that will fit the screws on the
face plates."
I will take fjm's word that the screws are Posidrive #1. I don't
know. I am not certain I have ever seen a Posidrive driver. But I
have never had difficulty using any small phillip's head screw driver
that fits in the cross on the head of the screw and have even
successfully worked on them (very carefully) with a small flat blade
on a small pocket knife. (I occasionally end up working on my
harmonicas in the middle of nowhere with whatever tool I have
available in my bag or pocket.) It takes patience and firm pressure
to keep the toolhead in the screwhead while you turn the screwdriver.
If the Posidrive #1 does not do it for you, there is a low tech
alternative: try your hand operated screwdrivers again, this time with
better pressure and care (so as not to strip the inside of the
screwhead).