Plumbers possibly stole something anything I should do?

Had the house repiped a couple months ago. There is an attic access point in the closet in my office. Nobody ever goes in my office other than me. The plumbers were in there alone for attic access.

My office is themed as though it is Indiana Jones’ office. I have a bunch of adventure-y type things in there including authentic ancient artifacts and tools and such. It’s supposed to be as though it is Indiana Jones’ office from the 1930s.

Anywho, I had a 4,000 year-old terracotta bust on the bookshelf and it’s not there anymore. I have a bunch of artifacts in there so I didn’t notice it missing until now.

I can’t prove the plumbers took it but nobody else ever goes in that office and it is definitely missing now.

Any thoughts on what, if anything, I can or should do about this situation?