I think belt rig was renamed chest rig, I’ve not seen belt rigs for a long while. Chest rig seems to have the exact same stats.
camo tank is a good point, I’d expect a lot of those on soldier corpses and in military surpluses.
As to penknives… I’m pretty sure I saw one drop from some random zed I battered into goop.
one. I’d give them a chance to spawn in sports goods stores and hardware stores, but honestly do we really need it?
A toolbelt/belt rig that actually didn’t encumber your torso would be a nice addition, since y’know it’s around your waist like a belt.