Back about '80 or so, I showed a couple of Brown Swiss / Angus cross steers. One made the premium sale at our county, back when only about the top 25% of 100 or so sold, the other was 4th alternate (for the premium sale) cross at the Tulsa State Fair, meaning he was in the top 20% or so of steers there. They were, for that time, very moderate sized, and fairly thick. Everybody thought they were Maine's...
As I recall, back in those days, Amerifax or Beef Fresian cattle weren't uncommon, and were often found in the pedigrees of percentage exotic cattle. Not sure if the exotic papers would've indicated those as any different than Holstein...