I am trying to recall the name of, and thus find the website of, a company that used to make very long achromat doublets telescopes, I think in Pennsylvania. Their website made a big deal about their QC and they sold all sorts of accessories. They made up to 8 inch lenses, if I recall, at up to f/15.
I found it! D&G. Thanks anyways.
TeleVue 85 f/7 // Astro-Physics Traveler 105 f/6 // Astro-Physics 130 f/8.35 // TEC 180 f/7
Coronado 60 DS
"Scopes, Brains and Wisdom--but no Beauty"