Yes it was Martin and King. They were originally a Melbourne railway carriage maker, based at what was then Westall in Melbourne (now called Clayton). They were owned by Clyde Industries, also a railway carriage maker in NSW. In 1954 Martin and King were contracted by Regent Motors to assemble German VW CKD kits - they also had experience assembling British Wolseley and Riley bodies for Australian sale. They had been chosen by Baron von Oertzen, who was the boss of VW South Africa and also a board member of Regent Motors (and later Volkswagen Australia Pty Ltd). In those days fully imported cars drew extra tax penalties, so there were financial incentives to make VWs locally.
The British car kits Martin and King were used to had needed lots of hand fitting, adjustment and modification to slot together. By comparison, when they started assembling the Volkswagen kits, they were the most accurate fit they had seen and fitted together perfectly.
In 1957 the new Volkswagen Australasia Ltd company was created, 51% owned by VW Germany, and the other 49% shared by Melbourne's Regent Motors, Sydney's LNC Industries (Lanock Motors) and Clyde Industries. The Martin and King business, and their Clayton factory, was purchased outright. The factory was expanded ten-fold over the next few years as VW aimed for over 90% local content. That came to an end in 1968 with the return to CKD assembly. The factory was sold to Nissan in 1976. Nissan ended Australian production in the early 1990s and today the site has been subdivided, although many of the buildings are still there. It's a Linfox depot, and also the home of Holden Special Vehicles.
Martin and King kept their railway business and moved to Port Melbourne. They built many of the stainless steel rail cars used on the Melbourne train system, into the 1990s. Not sure what happened to them after that.
