There are a huge variety of vintage rings available out there.  It may benefit you to consider a few things before you make a purchase:

1. The settings on authentic vintage rings were almost always made with prongs rather than being glued. If there isn’t a pronged setting then do your research because chances are good that the ring isn’t a vintage piece.

2. The ability to resize a vintage ring depends upon the design of the ring. Some styles are relatively easy to resize while other designs make it extremely difficult to do so. Be sure to consult a master jeweler about resizing before you make your purchase.