7-valve + eye dual-wave radio or radiogram, magic eye tuning.
There is a model 810S, with a different circuit - a stereogram. This model, the 810, is mono.
The radiogram version (Somerset) of the Columbus 810 has two speakers as shown on the schematic, the table cabinet (Plymouth) has one 10" x 6" Elliptical speaker fitted.
Intermediate Frequency: 465kc/s
Service note from the schematic:
Distortion: check leakage on R/G switch - B+ to diode load
General Construction Notes for Radio Corporation of New Zealand Ltd: The first digit of the serial number typically indicates the year of manufacture of RCNZ chassis' (although not the decade - that requires a little knowledge of the valves, construction, etc). Sets from around 1934 onwards were often (but not always) constructed in a distinctive pressed 'baking pan' style chassis, seemingly unique to RCNZ.