Now that the US distributor didn't resign (they were also in charge of repairs), I'm not entirely sure.
I've contacted ST Dupont several times with no response.
You can try the old place to see if they are still handling repairs.
Colibri
1425 Cranston St.
Cranston, RI 02920
Phone: (401) 943-2100
Toll Free: (800) 556-7354
Fax: (401) 943-4230
I did find this, this morning!
S.T. Dupont, Inc.
108 Corporate Park Drive
White Plains, NY 10604
Phone: (914) 701-5200
(800) 341-7003
Fax: (914) 701-5201
I hope this helps
~Mark