I was wondering if there are any foot numbers or date codes on these reels, I only have one and haven't looked ?
No date codes or serial numbers that I am aware of.
Johnson came out with the Century 100 in '55. The reel had a couple of changes between 1955 and 1962. Along with a few other changes the name was changed to the 100A around 1957. It was changed again to the 100B in 1962 and stayed in production until 1979. It came in various shades, of green but there is also a rare all black 100B. The best way to date them is to become familiar of the different variations and there production/distribution dates and go from there.