Help with my S.T. Dupont lighter

[markem]

Best wishes on identifying the lighter. From the looks of it, you may want to have it cleaned up by DuPont, so I'd send it in to the service center for your country, have it cleaned and checked out. Even if it isn't a real DuPont, it looks old and may have sentimental value to you and your family, which argues for getting it leaned up and working properly.