The Fine Things are Always Hand Made
So...I'll add a link to an eBay auction I was bidding on...it appears to be an AM Masterpiece chassis, but with the layout of an FM version...
Maybe pretty rare?
No - is the normal AM/SW Scott Masterpiece receiver.
The red ultra shortwave band my be confusing you. Pre war TV sets received only the video signal. One needed a short wave radio for the audio. The audio was broadcast in a high frequency above what many home radios with short wave could receive. The 5th SW band is red on your photo, and some Scotts were in white.
No - that is not an FM set. It is a standard AM/SW Scott Masterpiece.
The ultra high frequency in red was a set option for receiving the audio of TV broadcasts. The pre-War TV sets received only the video signal. TV broadcast industry was new and still largely experimental and development was was put on hold during WW2. Many home radios with short wave bands lacked a high enough frequency to receive TV audio.
One FM/AM/SW Scott Masterpiece has turned up and it has a wider chassis, with the right side extension like the FM Phantom has.