Yeah, thanks. I emailed Autecnica and they said all steeringhweels/hubs sold in Australia have to meet the adr/10 standard.
The Momo wheel has a smaller centre hole than the autotecnica one. It seems I can put a Momo wheel on an Autotecnica hub just by using a Momo earth ring, but I'm not sure if it would work the other way. It SHOULD, so long as the momo hub does not have a smaller internal diametre than the autotecnica one. If it did, the Autotecnica earth ring would not sit inside the Momo hub.