So I just received a 6x6" piece of heat absorbing glass from a member. I've sent him a PM to ask but figured I'd ask out loud as well.
Where exactly does it go? I took off the light head and managed to put it at the bottom of the upper bellows, right above the negative stage. It fits, but doesn't seem ideal since it doesn't really "clip" in or anything, just sits there.
I'll look at the exploded view in the meantime.