Late to the thread but those are the same mirrors mine has and I bought my '84 new. I think they called them "West Coast" mirrors and mine is the long-bed deluxe.
The window trim came black but over the years the black has mostly come off and the chrome is underneath.
Cheers.

 

They call them mini west coast mirrors. They are smaller than the ones on same year Broncos and other full-sized trucks. I bought my '88 new. It was a DLX and the bumper and trim were black and so were the mirrors. They were exactly like the OP's except they were solid black. Between them and the Outlaw II wheels on it I'd say they were dealer added. I bought a left over somebody having twins decided not to buy.

 

Back in 1984, trucks weren't required to have Monroney Labels like cars, so I never got a "window sticker". I'll check the rest of the paperwork in the glove box but knowing how these mirrors are attached to the door, I'd have to say they were factory installed in Japan. I believe the beds were installed in California but it the mirrors had been installed post-production I'm sure there'd be some indication of rust where the holes in the door skin are. I'm assuming it was part of the deLuxe package which included the double-wall bed with tie-down hooks inside in the corners, not outside like the base truck.