Re: Z axis way cover
If it was me, I would use what in the military we called "EB Green" or "EB Red" duct tape (used by Electric Boat to temporarily hold anything on a submarine).
Search for "3M Performance Pro Duct Tape 8979" or "TapeCase 8979 Duct Tape". Amazon carries it. You can get it in black. Wipe the surface with alcohol to clean it thoroughly before applying.
Another option is you can get some sail thread and sew your silicone repair tape in place.
Tim
Tormach 1100-3, Grizzly G0709 lathe, Clausing 8520 mill, SolidWorks, HSMWorks.