I'd have to double check to be sure but I think IH released the 1350 in '80 and the 1250 had been out for a while by that time.  I'd have to ask dad when they bought their first 1250 but I remember when they traded it for a new one in early 1990, they had to have bought the first one prior to the drought of '83.  At that time they were farrow to finishing 100 sows and there was hardly ever a day that the grinder didn't get used. 

We still have the 1250 for cattle feed but it's only a load or two a week now.