Hi Tom!In the Rider CD's, I see a Philco 46-280 and a handful of 41-xxx models, but no 41-280 listed between 1926 and 1947. Sometimes it's that way, and I'm not sure if the Rider documentation is incomplete or what. Each of the Philco radios I saw were made in WWII years, or shortly afterwards. So I'll look for chassis that use (2) 7B7 tubes and a 7C6.
By the way, I have a NOS 7C6 tube if you need it. I bought a bunch of NOS tubes and I've kept many for my own personal stash and I'm selling the rest on eBay. Every one that I've put on the tube tester checked out 100%, so I got very lucky with this purchase.
Wayne