Homemade Dash

Ok, found it. So is all your air provided by those 4 or 5 ~3" flexible ducts? How does that work?
It works well. It blows plenty of air. I don't think it's in any of the pictures but I used some rigid flattened oval ducting for the windshield defog/defrost which works well also.
All that said, the cabin air doesn't cool sufficiently to keep me from sweating here in Texas most of the year. My coach has two new Coleman Mach units and one is mounted forward where the vent used to be. The holes are the same size so I swapped the vent and AC location as some other owners have done. When it's hot out, I do travel with the forward house air and the dash air running.