[Arran]

Without documentation, all we can do is guess. And Philco does not include Radiobar production in Philco Furniture History as Radiobar was a separate company.

Anyway, to answer your previous questions:

Is it documented where the cabinets were built?

40-507P - 5,001 built by R. Prescott & Sons between 5/26/1939 and 10/10/1939.
40-170CS - 3,500 total; 2,500 by Watsontown Cabinet Co. and 1,000 by R. Prescott & Sons. All built between 8/9/1939 and 9/12/1939.

Anyone know what the dimensions are for the Philco 40-507P?

Height - 34", Width - 31-5/8", Depth - 17"

Ron;
  That is very interesting, R. Prescott & Sons also manufactured the cabinet of my RCA Radiola 44 and 18, there is a plate on the inside of each cabinet at one end. R. Prescott & Sons was located in Keeseville, New York and was established in 1840 as a furniture and sash manufacturing company, which later added blinds, doors, mill, clock cases, radio and TV cabinets, and coffins too if you can believe it? (hmm, my Radiola 44's cabinet does somewhat resemble a casket, now I know why.) It would make sense that Philco would outsource cabinet manufacturing to a firm in New York state since it's right next door to Pennsylvania, especially such a well established one that did have some experience in manufacturing radio cabinets already.
Regards
Arran