Email [log in to unmask] They will do all kinds of custom and stock glass
components. The glassmasters are NIST traceable and they call linear accuracy
of
±0.0001", with orthagonality of 1 arc second.
I used them to make a qualification board for my previous employer. I bought a
variety of 4 parts with quantities ranging from 8 to 25, and believe I paid
somewhere between $50-150 per part.