I've turned up plenty of seats looking for hidden treasures,and haven't seen one either.Most of the trucks I come across are all Lower trim level trucks,so it's highly unlikely they'll have them.

81-Explorer,are the caddys Plastic?

 

There were more than two versions with the D8TZ one being the last.

The one I saw for the riffle was in a 1973 F-100 Explorer. It was metal, with a metal door and latch to lock it. This was a good 30 years ago now.

 

I saw one of those in a junk yard once, but it was missing the doors, looked like it had half sliding doors like a closet door. It was held in place with the cab bolts behind the seat.