Shannon, I would guess fifty's or early to mid sixties. Like I said I have seen them advertised since then. Don't let them brow beat you Buddy, you can get even with them at the classic.
As for the hair getting in the food, that is what keeps you from wondering just what is in that blood sausage, :and where did the blood come from exactly.....
You're too busy looking for hair in your food, and not thinking about what you are actually eating.....and just which part of the intestine is that natural casing from......