A mainstay of the football casual wardrobe were Lyle & Scott, Pringle and even Gabbici sweaters AND cardigans. I do not know what boy racer casuals wore, but I assure you that expensive golf knitware, preferably in baby pinks, light blue and yellow, was where it was at with these geezers. FACT.
I'm guessing that you were not a teenager/young adult during the late 70s to late 80s when this casual style was popular with a strata of young men in Britain. But it was only a strata. I assure you it was nothing like as exciting as you seem to imagine it was, and most of their contemporaries...