M_Boats: Thinking of buying a Montgomery 15

Greetings: I currently live in Sacramento, CA. I own and sail (or at least try to) a C-15. It is a fun boat, but the wife hates the tippy feel to the boat, and am having problems finding crew at times. Saw a Montgomery 15 parked by the lake, and since been doing research. Have heard a lot of good things about the boat. I did find one for sale, but it is listed as a Montgomery 15 Guppy. Looking at the pictures, it appears to have a smooth hull, not a lapstrake hull. It is definetly not a Guppy 13, and looks to have a retractable keel. My main question is, could this be a true Montgomery 15 or is could it be something else? The owner does not know much about it. Any advice is sincerely appreciated. Thanks- Rob