G'day Dutch
The only Aussie made frames I can think of were the Paul Sly copies of the Rotrax speedway frames and Don Staffords Alstar slider Dirt track frames , they were closely modeled on Elstar frames, so closely in fact I used one of Don's Alstar diamonds in my Elstar/ JAP 84s after a prang, the only difference being the Alstar diamond had taper roller head stock bearings , the Elstar used bushed pivot.
No doubt there are others, as many Aussies had Hagon copies made and there were a lot of home built Dirt Track specials built in the 60s and 70s, one that comes to mind, in the 60s, is the Philmac Special which used a layed forward motor , it formed the front down tube of the frame, ie a stressed member, cannot for the life of me find a photo of it, I have been trying for a while to track down some info on it?, them, as apparently, according to info I've discovered about six or seven were built.
Foss