Don't take the photos on Ebay as gospel Pete, they frequently just use stock images which don't always reflect the type of plug fitted to the specific adaptor. I'll have a look through the adaptors that I've got lying around (I've got drawers full of them) to see if I have anything you can adapt. I know I should have at least one for a TalkTalk box but I'm not certain they're the same because the TalkTalk Youview boxes are made by Huawei so they may use a different chassis socket.
Cheers Ken, that would be great.
The centre pin is really narrow, maybe just a mm in dia and the outer sleeve is stepped at the end.
I've att'd a few photos if it helps.