Can the Museum folks not pass a background check?
The way the law is written, it appears that the museum would have to return the firearms to their legal owners before the law takes effect. Then, after the law takes effect, the owners would have to take the firearms to a licensed dealer, who would then conduct the required background checks. After the museum passed the check, the dealer would then transfer the firearms to the museum.
And then, after the exhibit, the firearms would have to be taken back to a licensed dealer and their original owners would have to pass a background check in order to get them back.
Aside from the fees and the time and the hassle, it’s actually possible that some of the owners wouldn’t be able to get their firearms back afterward. Who’s going to take that risk?