Very nice job, that should keep the coach warm. On my 06 PT the unit under the drawer in the front had a very small outlet like yours, I cut out the wood to match the front of the heat exchanger and replaced the grill with a larger one I had to make out of two grills cut and welded together. Now it heats the front without heating up the whole dash.
I really like the big unit in your kitchen, mine has two units side by side, I also opened up the grills on those.