With the help of several kind people at the "Antique Radio Forum" and Mr. Philco (Ron Ramirez) this radio has been identified as a Philco 42-PT-26 originating from 1942.  According to non-published information of Ron Ramirez the earlier models PT-26 (1940 and 1941)and later 42-PT-26 are almost identical. All models tune up to 1580 kHz and have the same tube line-up and cabinet. The difference is in the dial scale. The PT-26 from 1941and 42-PT-26 have "PHILCO" in large and "TRANSITONE" in small letters on the scale, whereas the January 1940 (mid-season) PT-26 has the script lettering just the other way around. The PT-26 pictured on page 133 of Ron Ramirez' book "Philco radio 1928-1942" acually is a 42-PT-26.

The Philco 42-PT-26 is a super heterodyne receiver with an IF of 455 kHz. Tube line-out: 7C6, 7B7, 7A8, 35A5 and 35Z3.

Unfortunately the original backpanel of my radio is missing. I would welcome a clear picture of this part for reproduction purposes.