6-valve, 5-band bandspread radio.
The date of the set is an estimate from the Rola speaker code (25G1). The 'F' on the ARTS&P label indicates 1939/40 - but Bandspreading was only introduced in late 1939/1940 in the model 75 from Radio Corp NZ with other brands following suit from 1941.
The model code appears to be stamped on the chassis by the speaker plug (it could also be the serial number, but this is an unlikely small number given the size of Westco).