The 'Oxford' brandname was introduced in 1935 and lasted until 1942.
Oxford was manufactured by Webbs Radios Ltd, they were distributed by The New Zealand Express Co. Ltd. Currently there are 5 documented models.
The in-house brand of The New Zealand Express Co. Ltd.
The last advertising seen, in 1939, looks to have 1937-38 models listed. After that there is text advertising for radios and repairs right up until the radio industry was shut down to concentrate on war production. NZE do not appear to have started up with radio again once peace resumed, and most advertising shows they instead concentrated on freight and logistics.