Dorien
I suggest that you talk to Paul Hurley as he is the leading specialist
with these engines and it will guarantee that you get the correct type
of bearing. People are selling ones that will fit but are not suitable
and all require some modification. You cannot just buy bearings and
you may make a costly mistake.
Alternatively you could contact Britain's leading supplier of pistons,
bearing, chains and tensioners for the rarer cars
http://www.fwthornton.co.uk/
They've been in business since the twenties and are absolutely
first class to deal with. I believe they have some original stock.
I can't think of people better qualified to advise, though I dare say
Geoff Dowdle will have comparable contacts in Oz. Paul Hurley has
piston rings made in New Zealand for instance.
Ashley