The Audi 50 is a VW Polo with different badges, dropped from the range because it was pointless to compete against themselves with an identical model. The MkI Polo long outlived it. VW had the platform all along, cos it was their baby to start with. Golf II didn't clocks along until 2 years after that platform was consigned of the bin.
My old Ma was a director at the then oddly named VAG, the UK importer, itself an independent company owned by Lonhro. She retired about 1986 and somewhere I have reams of period brochures, books, some models, key rings, at least one Audi Sport rally team jacket, all sorts of guff. I ought to make the time to root through it as some of it might fetch a few notes on the bay.