The 482 was a belt driven 11hp Briggs, not a great engine, it's well known. When you jumped to the 582 you had another Briggs, although better the twin just wasn't what customers wanted in some cases.
Remember that loyal IHCC customers were sold on the quality and durability of the Kohler engines right from the start. Traditionally the 12 HP Cubs outsold most all others (once the 12HP entered the race) and was "just right" for most chores, just like their old 127 etc which maybe were due for a trade in. The K341 was a shaker in the 1650 series and we now had the 582, so it was ruled out.
Sadly, the 1282 got such a late start in the red series. It was offered as the model 580 by CCC