I have a framed print of images from Casablanca (Bogart and Bergman), Rick's etc, which is a pencil drawing ( think) that I bought some 30 years ago. It was bought framed and is a limited edition, this one being 199/300 and is signed in the artist name Gregory. There are no other markings on it and I have searched all over Google etc and can't find anything about it. I would like to identify the artist and put a valuation on it. Can anyone help at all or advise me how to identify it?

If the poster is not officially sanctioned (it should be clear, there will be some kind of marking from the movie studio and authentication marks), it's worth very little, even if it's a limited print run. The artist's name is very little to go on since anyone could make an unauthorized print. The only way to know for sure how much it's worth is to ask an appraiser. You mentioned that you think it's a drawing but mention a limited edition number -- it can't be a drawing and a print. If there's an edition (199/300), then it's a limited print of (possibly) an original drawing. If you don't want to get an appraiser, you might want to find a local film aficionado group (try meetup.com) and see what someone there would pay for it. Generally appraisers are very conservative and they will lowball you an estimate (unless it's an appraisal for insurance purposes, where to be conservative means to value it higher than you might think it's worth just to be on the safe side). You might get a better price by someone in a Casablanca fan base than from an appraiser.