The two I mentioned are:

Northern California- turners auto wrecking
4248 S Willow Ave
Fresno, CA 93725
United States
turnersautowrecking.com
They have many of these old trucks and countless engine parts
A lot of ready to go sheet metal, front and rear fenders of various quality etc, also had a couple AD panel trucks too when I was last there

Central Saskatchewan - Amigos auto wrecking
Clavet, Saskatchewan
amigosauto.com
They usually have a half dozen AD trucks in the lot usually all 1 Tons or larger but also many cars of the same generation