All of this brings to mind my days of modifying Athearn cars, since they and MDC were the only games in town.  In about 1970 I made a Santa Fe Fe-26 (40' double door box) by cutting up the Athearn model of the Fe-24 50' double door car.  I took one panel out of each side, with corresponding cuts in the roof.  This resulted in a 43' car, but it was distinctive and as far as I know, no one who saw it in that era ever realized the difference.  Even better, it was painted boxcar red as far as I can recall because the Floquil mineral red hadn't appeared yet.

The mention of the 14 roof panels triggered this memory.  I must have cut the panels in such a way as to preserve the spacing of the panels, because I worked with two end-roof-side pieces.

I may still have this car.  All of my Athearn cars that once operated on the club layout I belonged to are in one box somewhere.

Ron Merrick