18 century with jianding seal. what is this?

I wanted to find out more about this mark. I tried to do a bit of research of the item in question. But i need somone who has a more seasoned view. The seal is black, not red. And it seems to be a Qianlong 1795 mark. Now I was told this wax seal was placed on works before 1945. But this does not make it a period piece. The seal is next to the mark. I paid $500 for this as a period piece. I do not buy replicas or reproductions. So any help would allow me to get  my money back. Now I just because it bears a wax seal does not make it fake; Just not older than 1795.  Thank you very much for your help. NOTE: The whole vase was not displayed to protect the auctioneer.