Have you had a look at the painting out of the frame? Originals may have something written on the stretcher strips by the artist. Sometimes artists paint on pre-stretched canvas, but most artists like to stretch their own canvas. If this is the case, then the back of the canvas will likely not look very neat and tidy and may have an excess of canvas folded over so the canvas can be re-stretched at some future time. If the canvas is linen it will be brown on the back; if so it is probably an original. It is also entirely possible the painting was done on canvas board or some other matrix than canvas.
If after checking these things out and there is no writing on the back, or if the canvas is cotton duck (white colored) or if things look too neat and tidy, then take the painting to an art restorer and appraiser to determine if it is an original or a print transfer onto canvas. I'm just guessing, but I would think a print transfer might be shiny looking whereas the real thing may be more flat or matte looking. Look in the phone book and call an art museum for references to a competent art restorer. Then call the restorer and describe the painting and what you found on the back.
Good luck. That is a nice painting. If it is an original, it is time to have it cleaned and varnished by the restorer. Do not ship the painting but hand deliver if there is any question of it being original. They may need to see it to determine this, but it would be worth the trip to know for sure.
Les
