Hey guys,
thanks for all the hints. I think I have found what I was looking for. I have talked to Johnston Aviation Services and they said that their aircraft are not available for endorsements these days because they are too busy.
Also the Aero Club at Archerfield doesn't own the baron anymore. Caloundra, Flight One, Lylidale in Melbourne are the places so far to go? Have to check out Tamworth.
Thanks again.