This can be found from many vendors by using the DIN standard.
I think it is DIN 46346 connector, the size needs to be defined additionally, but I guess it may be 6.3x0.8 or 1/4"x0.8, and the cable size.
Ones made of phosphor bronze are better than brass.
DIN 46346A has a sort of tail
DIN 46346B is without the tail
And then you need the casing for the connector, but the vendors usually have them.
-Jouni