Brickdoctor

I did notice that. However, the model in those pictures has the six turbolaser turrets and two more rounded ion cannon turrets lining the superstructure, as opposed to the Imperial-II's eight identical turbolaser turrets. I can't find any solid information on which of those features is a constant, but Wookieepedia says that some of the communications arrays/tractor beam projectors on the Imperial-Is were retrofitted with the Imperial II hardware, so my thought is that that might be a model of the Devastator from Empire? That's the only thing I can think of. You're right; the model in Star Wars as seen in the opening chase clearly has the vertical tractor beam projector between the bridge shield generators.

Sorry for the wait. Tags awarded!