I just replaced the AC on the 66
Caravel. Previous owner had the Coleman installed in the original vent hole. It placed the AC box precariously aft and without support. I replaced it with a new Carrier Low Profile I got thru Palomino and installed it in a new forward location, then put a 4000 series Fantastic Fan in the old opening . It all worked out well. The AC now floods the living area with air and the Fan, when used, is located by both the Lav and the stove (Caravels are tiny.) Outside profile is cleaned up too.
Now, I am doing essentially the same on the 69
Caravel. But, folks, the later Caravel already has the AC mounted forward enough so as not to be a problem. The new Carrier Low Profile will replace it and the Fantastic Fan will be mounted forward. By the way, got the fans from Palomino too.