Aeromarine boats
 

My understanding is that there were only ever four boats called Kiekhaefer Aeromarine;

KAM I = 36' Cigarette
KAM II = 36' Bertram Competition
KAM III = 36' Cigarette
KAM IX = 36' Cigarette

Can anybody tell me what happened with the five boats in between III and IX? Why such a big jump? Were these other boats factory spec boats that just carried other sponsorship logos, such as Dry Martini? What am I missing here?