Hi Matt & Angie,
Welcome!
Where in Michigan are you? You should check out the Midwest Meet and Greet coming up in May!
Yours is certainly one of the older ones in Michigan...I've heard of a '77, and a '78 or two, but that's about it. Sunline didn't get a dealer up here until around that time, and production was so limited that very few could make it up here from people going to buy them in PA.
FYI- the Coyote's were a special line developed sort of as an off-brand. I've never actually seen one, so I imagine they are quite rare. They aren't associated with the newer Coyote brand though. Most of the Coyote models were mirror images of Sunline models.
So yours is probably still a 12 1/2' MC, assuming it is that floorplan.
Jon