Grateful thanks to Bill (AC/HL) and Roger (G3VKM_Roger) for their kindness in providing me with three Plessey 7-way sockets (a.k.a. Pye 'Westminster' power connectors).
I'll be putting them to good use with some audio test equipment I'm restoring (pics to follow in due course via the 'Success' thread).
Cheers!
Guy