In case anyone wants motor parts for one of these. There is a home-made compressor made using the bottom end of what looks to me like a TT250 or TT350 motor at the tip shop at Benaraby (near Gladstone, Queensland) dump.
There is no mag cover but the clutch cover looks OK. There is a homemade air compressor head bolted on instead of the normal head. There is a big pulley bolted to the mag flywheel. The kickstart shaft hole has a plug fitted. The engine number prefix is ?Y4 (sorry don't remember first digit)