As an example I downloaded the image https://www.britishmuseum.org/collection/image/1613717051 (~1 MB, 2500x1973).
Still good enough for many use cases, but it limits personal prints.
[1] https://www.britishmuseum.org/terms-use/copyright-and-permis...
Some other countries have more of a laboriousness based theory though.
Further, you're saying that artifacts plundered from colonialist rule should then be restricted to the people they've plundered from under restrictive licensing terms?
Here we go...
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ps. both my shallow dismissal and your OT flamebait are discouraged here, so let's call it even and move on
I'm saying they have the copyright.