64 M20c Avionics Cover Sealing?

We are working on a 64 M20C Mark21, it does not have the "forward windshield
speed mod", still the factory design. There are two panels in front of the
windshield on the outside that cover the avionics assembly inside. They
have been sealed with silicone so many times that it took us 4 hours to
clean them up. I don't want to use silicone again. I'd prefer to use some
sort of pliable, removable sealant.

What is the preferred method for sealing those two panels (actually, there
are three as there is a small narrow one that covers the other two)? And
what do you use to seal the screws?

Any help would be appreciated?

Thanks in advance,
Alan - please remove the obvious email address extension to reply via email.