Alright, I’m sorry if this doesn’t really fit but my family and I have been trying to solve something for quite a while. The statue is around 4’ tall and is of Venus. It’s either marble or plaster, we can’t quite tell. My grandfather stole it in the 1950s in Massachusetts after the floods. He’s long since past away and we’ve been trying to figure out where the statue originally belonged.
I would recommend checking newspaper databases for the period of the flood you mention and see if it is mentioned among missing items or artifacts. If it is a genuine antiquity, I suspect it vanishing in a flood would have at least merited a brief in local or statewide papers in Mass. commercial options are available. Your state may also have some free resources through colleges or libraries.
This is a fascinating situation you have found yourself in. I hope you will tell us what you learn.
It should be pretty easy to tell if it's marble or plaster, probably by temperature and texture, but also by weight. There are other ways you could tell, but I hesitate to mention them in case there are any conservators in the audience...