Thanks for that info. On balance I'm thinking I'll remove the tourism=museum tag, as it feels a bit misleading to me and doesn't seem to match the Wiki's description of a museum.

I also happened to visit the area again recently and had a closer look while I was there. There's definitely no on-the-ground signage advertising tours, and I couldn't find any other info about them online either. So if tours are still occurring, they must be quite rare/intermittent.

tl;dr I'll remove the museum tag. I don't feel particularly strongly about it though, so feel free to re-add it if you disagree :)