GasMask is a new item,but it seems we cant get it in the map.We've spend a lot of time on looting Scorpion-7 and never find a GasMask.So I think maybe u can let us buy it from the store(including the radiation filter)
Since it is a new item it will most likely be added soon they just didn't have the time to add it yet. I am sure since it is in the default game it is still possible for it to be found in game just a little harder to find.
Well..its a "rare" rank item ,which means it'll be more common than "epic"or"lengendary" but after the 5hr looting,I got 3 shadowstalker but no gasmask.There must be somwthing wrong.