We believe that Australia produced the first three single hose scuba regulators.
The first was the 1952 Porpoise CA, made in Melbourne.
The second was the 1954 Sea Bee also made in Melbourne.
The third is this one. It is the 1956 Scubmatic and it was made in Sydney.
I have all three and they are all useable. I have the last Porpoise, the last Sea bee and the Scubmatic being dived in the bottom pictures.
Steven Taylor HDS SEAP.