Current Situation

Many results from Science Museum have the creator set to "Unknown maker".

Suggested Improvement

It might make more sense to detect this value and instead set creator to NULL. We should check to see if any of our other providers, particularly museum providers, have similar values.

Benefit

It's worth considering whether there is any useful/meaningful distinction between null and "Unknown maker" confirmed by the source, in which case we may decide not to do this issue.