Finally got around to trying to sell random alloy in my garage, but having trouble remembering how to figure the offset out.
If i remember right its the difference between the exact centre of the wheel width, (7in divided by 2?) to the flat of the bolt plate/hub connector thing. If this is correct then great. I have an offset of 45, but markings on the inside seem to say 30.7 (looks like a point '.' but could say 307)
just after some confirmation, cheers