statues are art, they are copyrighted to the original artist and should at least be credited for it. however if the statues is i think over a 100years old then its public domain, or at least much safer than just anything. if there is a main scene and there happens to be a sculpture in it, there isn't much anyone can say about you using it, because it was part of the scene. if you singled it out then they can get you on copyright infringement. in the end, is it really worth putting up a statue? since these are for sale, unless there is something you did that made it different, made it artistic, it won't be that interesting. and your selling it on the merit of someone else's hard work.
---Mike Savad