That sounds like a neat little project! Are you a bit of a stargazer when not making mead?
I used to be. I've got a 16" mirror that I'd ground and mostly polished before a disc in my neck went boom. Now it sits there waiting for a miracle.
These platters wouldn't do for a scope of that size, but for an 8" they just might do for the base. Nice, solid, smooth surface.
Joe