Well, a lot of what this person says is fairly legit. Early versions of the Wagoneer had the same grille as the Gladiator pickup as you see here:
http://www.imcdb.org/vehicle.php?id=98865
Although some versions kept the old grille after this, like the 1967 2-Door Wagoneer somebody tried to sell me at Wildwood State Park nearly 20 years ago.
This grille began with the Super Wagoneer:
http://www.imcdb.org/vehicle.php?id=98865
But by the time AMC bought Kaiser, that grille was only on the J-Series pickup, and logo was gone in 1974. The Wagoneers of the mid-1970's(1974-1978) had grilles like this:
http://www.imcdb.org/vehicle.php?id=131422
Cherokees didn't.
There must be something on the Old Car Brochures website.