I came across this "Marathon" watch on the 'bay the other day while idly researching my 90's Marathon Mil-W-46374d. Not sure off hand if was from the same company, but I guess there's no reason to think it isn't.
Even without seeing the movement, the case design and dial layout mark it as a Russian Molnija movement. The SU, I'm told, stands for "Soviet Union", and probably date it to the 80's. The finish is a bit higher then I've seen in other Molnija's from this era (though still a far cry from the movements made in the 50's).
Shortly after getting this, I came across a Cardinal in a local thrift shop. These show up rather frequently around here, and a search on Google turns up dozens of identical looking watches. Thus, I wasn't surprised to find another classic Russian movment inside; the Raketa 2609HA. As I've heard it, the H series of movements were specifically designed to meet the more esthetic demands of western watch buyers. Not sure what differences mark the HA variants. As with the Marathon, the plates sport an 'SU' engraving.