1. Clothes badly painted onto nudes could be seen as itself an interesting/funny cultural artifact, and since it's at a library, you could have signs explaining the history.
2. I have no problem with Confederate statues being torn down or destroyed, since any perceived cultural/historical value is outweighed by other considerations. They are giant public symbols; little signs explaining "these statues were actually erected during Jim Crow and these guys were bad" are too...abstract.
3. Silently revising works of fiction seems especially wrong because we don't even know where the titties are getting painted over. The Roald Dahl edits weren't just removing "ugly" and "fat", they were also removing all reference to Conrad and at one point removing a reference to the color black applied to an inanimate object, a tractor I think.