My point is what makes it a trench gun is the parts not the manufacturer. What if another importer,maker decided to make trench guns like they have with regular 97s and 87s would those be legal. And since both my 97 s have had barrels cut and work to mark them cowboy ready prior to me getting them to use in WBAS. How do I know one of them didn't start out as a trench gun years ago. A butt stock swapped etc and such.
I just have a hard time seeing how adding the heat shield which is legal one one gun can be illegal on another. It like saying your boots are illegal because you had them resoled with the soles of another legal boot.