Projects Part ID: GM Heater

I bought this when I was building my '39 Chevy truck. It was too cool to let go with the project when it sold. I re-found it in an old box of parts this weekend. Any idea what it's from? I'm guessing the copper plating isn't stock---plated for cosmetics? I'm probably going to sell it, but have always wondered what its history was.

Appreciate any help!

 

Sorry for the extra posts. Haven't been on the HAMB in years and have forgotten the basics. I was trying to use the gallery thing but not doing something right...

 

I think it's a Canadian thing, that's where the Master name shows up the most.

https://www.ebay.ca/itm/227132367468?