Thanks for that. Yes, the back of the block has that flat pad, so not the original engine. Will check other numbers over the weekend.
And, sms777, the number stamped is the full VIN number (6F07 etc) and the car has spent most of it's life in Victoria (Engineered for RHD in year 2000) so don't think it's one that you've done. Thanks for the offer 'though.