Originally Posted by T-Mar

A 1939 serial code indicates a 1939 ot 1940 model. As noted by Mark, it is a "roadster" style frame. However, beyond that it gets tricky. The only men's roadster models in 1939 and 1940 with the single piece crankset were the Crecent Roadster and Rambler Roadster. Both were budget models and would not have come with chrome rims or a double brace front fender. The wheels also look they might be smaller than the 28" size found on these models. They look they may be 26" which would indicate a balloon tyre model. That would explain the double brace front fork and chrome rims, though it came with the three piece Triplex crankset. I guess we also shouldn't rule out a juvenile model, even though it does have an adult 50T chainwheel. Since sizes are hard to judge from photos, please post the tyre/wheel size and frame size. Both will help to narrow down the model.