I just bought an old Gordonson 10-speed road bike, and I'm trying to fet some details about the frame. Apparently these bikes were 'made' in Perth, Western Australia. Most of the components on it are Japanese (Shimano gears, Dia Compe brakes, WIN bars, Hantrade rims, etc).

The chrome fitting at the top of the head tube has 'tange' written on it - does this mean the frame is made by Tange, or just the chrome part in question?

Thanks