I asked Peter to post this, as much to share the images, (which are wonderful, Peter, thank you) as to get confirmation of possible origins. I thought this might have been Wunsch, but it is unmarked, and no opalescent casing left some doubt. Peter's role as relay post is much appreciated, and as isp problems are still causing difficulties here, I felt it might be better for Peter to post images from the UK.
Regards,
Marcus