The N.Z. Vintage Radio Project

Wellard appears to have been a short-lived brand sold by Sedley Wells Music in Christchurch (and possibly others). 

One schematic found inside a radio suggests the circuit was prepared for the Empire Piano Company Ltd but the back panel suggests the radio was made BY Empire Piano and that there was a distributor called Wellard Industries (N.Z.) Ltd.

According to the NZ Companies office, Wellard Industries Ltd was incorporated on the 20th Dec 1954, operating until 29 Jul 1991 when the business name was inexplicably changed to Cascade Liquor Ltd.  The only office listed is for Moray Place in Dunedin but this might be a later location.