Is there a way to get Scorpion Carapaces in Open World to build the Scorpion Armor set after completing the mission for it?

What good is this accomplishment if I can't craft the Scorpion Armor outside of that one mission because it is the only place I can get Scorpion Carapace?

You can get carapace from SMPL3 missions in open world. That is a chance reward. But I don't remember exactly what mission difficulty that was. Either I did the Easy hunting or medium extermination mission that randomly rewarded me with almost 2 stacks of carapace and scorpion boots. Other than that, dunno.