The ABS plastic banana wraps are used on newer Airstreams, but they fit vintage Airstreams (including Argosys) starting in 1969. They are a dark charcoal color and should be painted. You should expect to trim them to fit your application. Generally, hold them up to the curve, trim a little, fit again, trim a little, and so on until you get the fit you desire. These were originally installed with 1/8" Pop Rivets
Please note that all four versions have a flat area on them designed for mounting a reflector (VTS-376 or VTS-147).
Additional note about finish: Beginning in June 2016, Airstream is using a textured plastic rather than the smooth. The smooth is no longer available.