Should have gone through the thread, shouldn't I? (bad southern accent....sorry, watching Dukes of Hazzard!)
What size should they be, A24-13 and the 'M'?
Jan, the first 18 Catalina's shipped to the RAAF (A24-1 thru A24-18) were all PBY-5 model and because of the then neutrality of the US, all were given civil registrations so they could be ferried out of the US by Qantas pilots. So mate your ok with the PBY-5.