[Brad Winder]

I found this 357 a few hundred kms away listed on Marketplace in Saskatoon, Saskatchewan. I paid the seller, and my friend Doug picked it up for me. 

I have a U.S. 57, and I didn't know the cabinet was different on the Canadian version. It appears to be model 53/54 style cabinet, sans photofinish. We didn't sell the 53 or 54 chassis here, due to them being AC/DC.

[Ron Ramirez]

Your cabinet is identical to the USA model 58C. The Gallery shows a 58C in photofinish which is in error - my mistake from years ago.

The first version of the USA model 54C has inlaid veneer where yours has a routed groove. A later (initial 1935 model year) version of the 54C and 59C used photofinish on the front panel. The January 1935 (mid-year) 54C and 59C used a different cabinet.

The model 53C cabinet is very different.
https://philcoradio.com/gallery2/1933a/#Model_53C

Does your have the original metal back, or is it missing as it is on so many of these sets?

[Brad Winder]

Eeeeek! A mistake?   

The back is unfortunately missing. I haven't seen any in person, with a back. I wonder why they were lost so often?

[Ron Ramirez]

Probably lazy "repair" people not replacing them decades ago.

I almost never see any 57C, 58C or 59C sets which still have their metal backs. On the other hand, a stock 54C will not operate without its back as the 54 incorporates a safety switch which the back holds depressed (closed). Without the back, the switch goes open and the radio will not operate.

[Brad Winder]

Ah, ok. I assume they did that because the chassis was live? I didn't realize companies incorporated an interlock into the backs so early. I thought that was a very early 1940's development...

Was Philco the first to do this?

I have a model 53 with it's back still attached.

[Ron Ramirez]

Philco only did this on model 54. Model 53 does not have such a switch.

No, the 54 does not have a "hot" chassis. To Philco's credit, as far as I can tell, they never built an AC/DC radio with the chassis directly connected to one side of the line as did some other manufacturers, including RCA.

No, I think they were being extra safe/cautious with the design of the 54. Their later AC/DC sets had no safety switch. I'm not sure if model 38-14 or 39-8 (AC/DC) sets even had a back - if they did, I've never seen one. I know the tiny Transitone/Philco Transitone five tube sets of 1939-42 had backs, but otherwise no interlock or safety switch.