Yes I saw that thanks. The company who wrote the article have yet to come back to me. I don't think BT will know what one of these is, but If I see an Openreach van I'll ask them.
Deleted
This thread suggests they are now as rare as hen's teeth:
https://forums.thinkbroadband.com/dslrouter/4728354-sogea-faceplate.html
And so does this one:
https://forum.kitz.co.uk/index.php/topic,26785.0.html
Disappointing. This would have made things easier.