Do you think each model manufacturer actually tried to duplicate a specific covered hopper OR do you think some versions are accurate while some versions are half-accurate and still others are just bogus?
You hit it absolutely right. Some try to get it right, others try a "one size fits all" approach and yet others use their imaginations excessively. Athearn is noted for the last.
I don't think that's necessarily fair. Athearn may have put the wrong schemes on their 5250, but it's not a bogus model in and of itself. Accurail is just as guilty of putting the wrong schemes on their cars as Athearn.
The Accurail car represents a 4600 cubic foot Plate B hopper (see here for the AAR clearance diagrams:
http://www.emdx.org/rail/Gabarit/index.html) manufactured after 1971. The Front Range 3 bay hopper represents the ACF 4650cf hopper, which is a Plate C (taller and wider) car, also post-1971. Atlas and Intermountain both offer pre- and post-1971 4650cf hoppers, both of which are much nicer than the FR model. And the Athearn four bay hopper is a 5250cf hopper, which again is a Plate C car.
Of course, in terms of the paint jobs Athearn et al have put on these cars certainly does fall under the "one size fits all" category.
RCH
