I found a tiny "made by Kuwahara" sticker on a Puch entry level bike once... but that's the exception. Some manufacturers used details within the serial number, i.e., Giant supplied Schwinn's had a "G" prefix on some frame serial #'s. Most of the 70's and 80's suppliers didn't readily identify their product. If others have tricks, I would like to learn them. I have a fondness, and a strong curiosity, surrounding the entry level bikes of the seventies and eighties. Their history is sketchy at best, lost at worst. For instance, it's amazing to me that your Sutton, with it's level of quality, rivals the entry level products available at a bike shop at the time. Most department store bikes of the time are a step down in quality of components, frame material, and build construction.