So as many people that play DayZ like myself know, you have a player GUI instead of an inventory, this could be done by a change in the recourse pack, another thing is if you were to add scraps of metal + BOP + Gun it would give it another upgrade for example: M4A1 + BOP = Bayonette attachment, + scrap metal = rail + r700 = acog scope... maybe?
M4A1 bop is acog but you can craft a bayonette and also put you can put that on the m4a1 Now sure about the bayonnette crafting recipe