The serial number for the Model G is on the front cap to the left of the blue AlumaCraft tag. I believe yours is G 1139. Mine is G 789, and AlumaCraft informed me it was a 1952 model. They also kindly provided a scan of the Model G page from the 1955 catalog that I will try to attach when I get back to my main computer. I also recall seeing a short paragraph in a 1950 issue of Motorboating on the introduction of the model. I can say the G rows surprisingly well, but I haven't had mine under power yet except for a trolling motor. I also previously had a Model E, and I believe I prefer it over the G, but the G is more easily handled and fits fine in the back of a pickup bed.