After an intense fight in the big red barn in Anarchy Acres, I noticed some gun fire had destroyed some hay bales. For a second I thought I found a new box, containing crafting items that I could loot. Instead, I found an item so hidden even Epic forgot about it.
It appears to be the place-holder model for an item that they were going to add, and in this case it should have been crafting ingredients. It is located behind this hay: