I have a full-thickness 16" mirror blank, ground and part polished to a 1.8m focal length, with central perforation. Its been under my bed for a decade or two. The glass is the Schott equivalent to Pyrex. Is anyone interested? All reasonable offers considered.
How big is the perforation? How much do you want to sell it for? I might be interested. I assume it is about 2.7 inches thick? Do you have the polishing tool too?