I'm well aware of the apparent inaccuracy of the firebox on the MTH engine. I believe that the MTH Premier Blue Comet Pacific model was built on the MTH Premier New York Central Hudson chassis which, of course, is set up for a four-wheeled trailing truck. As a result, the two-wheeled trailing truck on the Blue Comet is placed too far aft. Thus, the trailing axle is too far behind the rear driving axle and the firebox is too long - by about an inch if I my recall is correct. It's still an impressive model in my opinion.
MELGAR