Am I missing something? Wouldn't the boxes be the same if the ammunition is for the same type of gun? Why would you have a different ammunition box for a Medium A than for a Mark V?
Why would they differ?
Same gun, same ammo. So why a different tin to put them in? www.foxhallmilitaria.com/wp-content/uploads/2013/06/WW1-British-Hotchkiss-Machine-Gun-Ammunition-Tin-As-Used-In-Tanks-image-3.jpg">
Your are both correct. The ammo tin is to all intents and purposes exactly the same. The only difference is that the tin for the Medium A has a blue stripe along the font with white stencil whereas the other tin has a red stripe with the appropriate stencil in white