I found another very good screenshot of this famous 1979 movie on another hard disc showing 2 boys in white shiny shorts at 17 minutes, I think one is from Adidas.
I own the DVD but forgot to recheck it completetly and currently, I’m very busy.
It’s mainly of interest of 14 or 15 yo Chris Makepeace (also in white and other shorts), but I don’t like him and his haircut.
So still needs to be checked, but I think there are mainly older “teen boys”.
Main entry, currently rating 8 (maybe a bit lower)
Please also note my later update(s).