The 3 link stowage fixture seems to show up in pre D-Day assembly pictures . Before that it seems they just added whatever track they could scrounge for extra armor . The narrow style track shoes all had the same bolt pattern , so you might see a tank with rubber pads carrying steel chevron track as spares . Note the groucer bars were for use with the flat rubber pad links only , so if you have steel track on your M-10 for example you can leave off the groucers from the side racks . Yes it would have been nice to have the extra side armor plates , but you do get a pattern in the instructions , and as for plastic ,I've used those plastic tabs that come on bread bags when I was out of sheet styrene . And I can see your point about the 30 cal , but as Pinky said , the Brits got rid of most of their turret mounted mgs . It made it a hassle to get out of a one hatch turret . The Canadians , gave theirs to their Infantry to mount on their Universal carriers , and I read a story about one unit , that claimed they " lost " theirs , in reality , they buried them soon after landing in France. And it sounds like Rubicon has plans for more stowage sets with more machine guns and stuff so that will be good for all of us