Darton have a supplier for Australia and im sure they would have a contact in each state so might be worth throwing them an email or doing a search.
Adrian has done a few sleeved blocks now and the work is gun so if in Sydney id be giving him a buzz seeing he's already strapped together many turbo B series and F sereis engines.
Freight on a block to Sydney wouldnt be that much either and well worth the peice of mind for your sleeving.
My 2c boys, can only speak of blocks ive seen completed, im sure there are other guys around though.
