Andy makes some important points.
We know that even if editors in the UK respect what the British Museum is doing and don't upload those images to Commons or Wikipedia; where they are public domain images under US law, it is just a matter of time before someone in the movement, anywhere in the world, uploads any of those British Museum images that are of old two D objects to Commons as Public Domain images that can be used without attribution to the photographer or the institution.
Of course large parts of the British Museum collection would involve images of three d objects. In those case we can't use the BM images, but outside of lockdown people can either go there and take photos, or if you can't get yourself to the British Museum with a camera, make a request via the London Meetup, and if the object is on display we can get results such as at
https://en.wikipedia.org/wiki/Miniature_altarpiece_(WB.232)
The chapter remains in the awkward position of liaising with institutions that regard it as acceptable to claim a non commercial copyright on out of copyright material, and of in effect advocating for a position at variance with that of the wider movement.
One option that the chapter could consider would be to shift policy and instead start to diplomatically lobby
UK Museum's
to, as Andy put it, stop "
trying to appropriate rights that belong to us all." Perhaps those on this list who are still members of the chapter might consider raising this for a debate at the next AGM?
Regards
Jonathan