I'd be inclined to just alter the museum.
First change would be to allow multiple CT with one person.
Artworks produced by artisans employed by the museum ( similar to priest in s temple producing faith) could be used instead of the current CT, but serve the same main purpose. Several different styles of art would be a nice option. Perhaps having some hard to produce, or requiring resources other than just artisans in the building..
Having several artworks of the same 'theme' - from the same person, or of the same style- could bring a little extra happiness.
A visual change to show each artwork in your museum would be a nice touch.
For those, like me, who are working on the achievements, a few more could be added here. Perhaps one for having all you museums 'themed', another for having artworks for distant regions...