The search begins.
To think I had a set of 5 of these coveted wheels.
They are Simmons 3 piece and Simmons, in order to consolidate, decided to stop making 13" wheels and handed the dies and the specifications over to a "company" in Sydney called Retro Wheels. Graham managed to get himself a set from them which took ages because they didn't know how to spin the rims. Rick came to the rescue with the name of a company in Victoria who had made his Ikara rims. Retro engaged that company to do Graham's rims and eventually he got his wheels.
P.S. I've just rung Simmons Wheels (or Tempe Tyres as they are now called). They have taken everything back from Retro Wheels who no longer exist. They are not aware of any 13" dies and even if they could put their hands on them it wouldn't matter anyway because they are not prepared to make any wheels under 15".