Thanks for the replies, I've been told by two different people this lead was part of an AV adaptor cable set, which comprised several stubby cables that interconnected to make the right lead for your needs. This was from the early 80s when many different arrangements were made for AV equipment, including phono, DIN and SCART (in Europe anyway). Such AV kit was branded as Altai but I can't find any details. Anyway this orphan lead is of little use by itself so free to anyone in UK (due to postage).
Regards,
John