Emmanuelle, You could go to New York City. Three schools come to mind:
l.Jewelry Arts Institute 2180 Broadway, NYC, NY 10024 (212) 362-8633
2. Metal Kitchen 113 Mercer Street, NYC, NY 10012 (212) 334-9394
3. C. Bauer Studio, Inc. 214 w. 29th Street, NYC, NY 10001 (212)643-8913
(granulation, chain making, stone setting in classical tradition)
The latter two are spinoffs from the first school. I don’t know how
extensive the enameling is, but the granulation is definitely covered
by all three schools. Check out the Jewelry Arts website.
Hope this helps.