If I remember the order correctly, as you look at the top side of the female plug (for simplicity) assign the pin in the lower left #1, the top pin in the center #3, etc.
#3 is supposed to be the external shield braid, so it is a chassis ground.
#1 and #5 should be circuit grounds, essentially chassis grounds, and you can verify this with a simple multimeter.
#2 is left signal "+".
#4 is right signal "+".
Many of the inexpensive CB's in the seventies used a 5 pin plug that was the same as the 5 pin DIN plug.
You can also get the male plug at many electronic supply houses or suppliers.
If you happen to know anyone who has an old TEAC tape deck that they picked up outside of North America, you can simply use the cable from that.
:have bought an old Fountain (a NZ make)receiver, it uses din plugs. Does anyone know how and if I can convert my RCA plugs to input into this?