One of the ways the A-Line Husky Stack differs from the Athearn Husky Stack is the walkway platform configuration. As shown here the platforms have different sizes on each size.

The A end (above and lower left) have two different sizes of upper platforms

while the B end (above right and below) have the same size of upper platforms.

Also noticable in these photos are the replacement brass details. They consist of Stanchions, Liftrings, Locator boxes and Load guides.

Husky Stack Walkways with Brass details - Aline Car