New 4.5" minor axis elliptical diagonal mirror flat.
I bought this diagonal from Earth and Sky Telescopes and Binoculars in March 2002. The 28" scope project is finally underway and I decided on folded optics (and a larger diagonal).
The diagonal has never been installed in a scope and is still in the original wrapper. This is how Earth and Sky advertised the diagonal:
"Custom made in Russia by the same people who make the Maksutov Newtonian telescopes. Superb quality featuring 1/10 wave specs, enhanced 96% aluminum coatings, astrosital zero expansion material, true 45 degree cut elliptical, and fine ground sides and back for accurate mounting. They don't get better than this. Zygo shows straight lines right off to the edge of the mirror."
$250 shipped. Paypal or money order.