[Arran]

From what I understand most of the post war Philco Tropic sets were either manufactured in Canada, or in Great Britain, without seeing the set from the back it's hard to tell which. I think it's likely that this was a British made Philco as the knobs are different from any I have seen on U.S or Canadian sets, this is assuming that the knobs are original.
With regard to the power output stage, a lot of Philco sets used a "screen grid inversion" setup so they could eliminate using a phase invertor/splitter tube, I've never seen this in a set with 7B5s but not reason it could not be done. A 7B5 is basically a 6K6GT or a #41 with a loctal base so an output transformer that will work with those should work with a 7B5.
Regards
Arran