Hi again Peter. Your ‘Duchess’ may be the name of the cabinet or model. The chassis was likely identified separately. Your radio looks to be a single (Broadcast) band model with power supply integrated with the tuner chassis. The RCC index for 1930-33 lists 15 Canadian-made Silver Marshall models. Two of these are battery sets (Models 34A and 35A), one is described as an ‘Automobile Radio’, and one as a ‘Midget superhet’ (Model 782-16), so this eliminates 4 of the 15. Your chassis appears to be either an 8 or 9 tube model, depending on whether the socket next to the large can capacitor at the rear of the chassis is a (rectifier?) tube socket or speaker wire socket. This further reduces the possibilities. If you could confirm the tube count and types of tubes/how many of each, that would help identify whether your chassis is amongst those in the RCC index.
