I don't think I can be much help locating the flame, but I think I can help you figure out what you're looking for.
Your sign was probably mounted in a bezel with a plastic 3D flame mounted at the top, and a part of the torch was also done in plastic and mounted at that hole (or stamped metal?). You can see a similar sign on my profile, sans flame. I think most of 'em got shot out by BB guns or worse. You can also see a similar sign here:
http://mnprairieroots.wordpress.com/tag/vintage-standard-oil-sign/And the whole sign, torch intact but faded here:
http://www.flickr.com/photos/agilitynut/4878199775/in/faves-20391451@N03/
Hope this helps.