I'm 6'4".

A problem that I've run into with vintage frames is that many have top tubes that are quite short. On the other hand, the now-widespread availability of long seatposts and tall quill stems from Nitto or Velo-Orange mean that seat tube length isn't as much of an issue that it once was. It won't be a "French fit", but it could still be a good fit.

If you're not set on a Schwinn, I'd definitely recommend the Bottechia that's for sale here.