In VIC they are legal and probably don't have to be centre bore located. The national guidelines states that they would have to be centre bore located. I have seen some that aren't. I personally would spend money on upgrading the brakes and changing the stud pattern that way. Unless you wanted to change from Ford to HQ. As the centre bore is the same ( 71.5 MM ) and the offset similar ( Ford +6, HQ + 13), simply get blank discs, drums and axles and get them studded accordingly.
thats where its a bit cloudy chopper, is an adaptor also a spacer?
Unless an adaptor has a zero thickness, then it also acts as a spacer.
From The Australian Oxford Paperback Dictionary, second edition page 8.
adaptor n. 1. a device that connects pieces of equipment that were not originally designed to be connected.
A spacer simply moves the wheel out further from the hub.
I can see the difference.