I agree, there is advantages to doing things yourself,i realize this is going to be very difficult,i knew Lynn Hepburn(Southwest Optical Technology's, in Tucson,AZ)he built a vacuum coating system from mostly surplus parts,and gave me a much better understanding of how these systems work,i have diagrams and a step by step proceedure for operating a v.c.s,however the diagrams dont go into alot of detail,and he passed away a couple of years ago.so im kinda stuck right now,however i have got some usefull info from you and other's.
I see it this way;this technology has been around for quite awhile,telescope mirror vacuum coatings started in the early 30"s i think, using limited money and resources, and some trial and error methodology, i do think this is within the realm of possibility, inspite of past unsuccesfull
attempts by other amateurs.