oK, Me, Myself and I is jammed right now. I'm gonna delegate this.
TR it costs about 60$ to coat a telescope diagonal. We need a AL or Enhanced AL coating, the enhanced AL has a oxide layer that boosts reflectivty 15-20% and lifetime goes up a factor of ten. I'm not even gonna dream about dielectic, at this point, because the only cost effective place to do that would be China, and it would need 4 chamber runs, or mechization to rotate the pieces.
TR,
Find some others like the guys below, but find one that can do the overcoated or enhanced AL, I can't find the website of the guy in florida that has AL overcoat. Tell Them you have 4 objects ,375 diameter with 4 faced pointed ends, the faces are roughly 1/8 inch triangles at 90/ Tell them a skilled university research tech will make a UHV compatable holder for the 4 pieces, about the size of a diagonal.
Tell em I will plasma clean it in argon before shipping, if they get nervous.
UHV means ultra high vacuum, and making UHV is nOT a piece of cake. A FINGERPRINT on the chamber wall can ruin your day, or at least 4 hours of pumpdown.
I gotta get Norms board out today, so you ARE hearby authorized to call around, Hint, dont tell em exactly what its for, say its a beamsplitter, these guys are small shops or backyard operations and its easy to spook them.
Something like this:
http://alcoat.net/al_1.htm
http://www.opticwavelabs.com/products.html
http://www.vacuumcoatings.co.uk/Aluminising.html
Chemical silver will not cut it. I have tried two of the 60$ kits on the market, this has to go vacuum. I'm not sure about sputtering, would prefer aluminizing or ebeam.
Steve