Dealer installed radio?

That's a 70 radio.
For a dart or duster with the rally dash only.

The rally dash for 70 was a one year only frame that was mostly a carry over from the 69 barracuda but with differences in the key hole location and provisions for a rotary glove box latch that was mandated in 70.

The radio hole and mounting stayed the same from 69 to 70 then changed in 71.