[Nathan Slingerland]

Comparing the 660 to 665 under-chassis pictures to your photo:

   

   

You've got a 660.

-> Part #32 is present on your chassis, not on 665
-> Part #39 is present on your chassis, not on 665
-> Part #71 is present on your chassis, not on 665

P.S. it turns out that the 660 and 665 use the same transformer and dial scale parts.

[GregL]

Well this clinches it then. Thank you for the in depth research Nathan.
I love this old radio but I'm afraid I'm a neophyte when it come to the technical chassis information.
Last question on this subject: Am I correct in dating this chassis to 1935?

[Nathan Slingerland]

That seems right - and that sure does look like a date on the transformer.

The other 660 based models were intro'd in June 1935:
http://philcoradio.com/gallery2/1936a/

and had been discontinued as of January 1936:
http://philcoradio.com/gallery2/1936b/

[Ron Ramirez]

Am I correct in dating this chassis as a 1935?

Nope, it is a 1936 model.

Chronologically speaking, the 660 came out in May-June 1935 with the rest of the then-new 1936 Philco line. The 665 would have come out in January 1936 as a replacement for the 660.

Just like a new line of automobiles used to be introduced in September of the previous calendar year, new radios came out in June of the preceding calendar year with "mid-season" replacements/additions in January.

[GregL]

Oh, of course this makes sense. Thanks Ron