I am working on a restoration project in Chinle, AZ of a church builtin 1909-10. The goal is to restore it to its original appearance inside and outside. We have outside done now and have just finished removing "modern" ceiling tiles, neon lights, etc. Underneath all of that, we have found thick canvas ceiling covering which has a printed design on it and clearly was applied in long strips probably from a roll. The underside is attached directly to the roof boards underneath wooden shingle roof. I have never seen any such canvas coverings in my whole career and I need to learn about them as quickly as possible. Pictures we have show it wasn't there originally; by 1940s, cellotex type ceiling tiles had covered up everything. We have no documentation about when it was put up, from where it came, etc. and believe me I have searched archives, etc. Contractor says to forget about it because it's earlier equivalent to current day drop cloth, plastic tarps, or what have you. The place is on the hist. register. both national and state, and before we do anything else, I have got to get educated about this stuff. Design on canvas is similar throughout whole ceiling area except for location of original altar/sanctuary where a different canvas was used, one with stars on it. Can anybody help me get started on learning about what we have here? THANKS.