5-valve broadcast band radiogram.
This is most likely the right code for this set, it could be a 545. Code based on service documentation images. Confirmation required.
Technical Information
Intermediate Frequency: 455kc/s
Chassis Notes(most schematics can be clicked to download a full size version)
Service information (HMV-535CRG-Dorset-Chester-radiograms-5V-BC-AC-1953.pdf) here