Today I bought an appropriate plug and socket for my charger. When I'm done, the socket box with the switch will be permanently wired into my garage wall and the charger permanently mounted in the car. I'm unlikely to use another PDL 56 series plug on the car as it's quite large and ungainly. I'm likely to use something like an IEC 60309 or an American twist lock on the car. I'll make an extension cord with whatever I fit to the car on one end and the PDL 56 series on the other. See Charging Socket for more details.
I must give many thanks to Geoff at J. A. Russell Glen Innes, go there for your electrical needs.