My light tourer/daily rider is a Made In Japan 10 speed road bike bought new by my late uncle at an LBS in 1974. I know some LBSs carried low end no-name bikes by certain manufacturers, and this one really isn't a bad bike. The frame geometry is perfect, good lug work, and it is equipped with Shimano 333 Eagle RD and Thunderbird FD. I am curious if anyone has a lead on Japanese serial number charts or info so I can tell who the manufacturer might be. Bike only says EXECUTIVE, and Made In Japan. Serial number is F7L04631. Danke.