Don't know what Lazy Days your referring to (Florida or Arizona) but they have coaches here in Florida coming and going all the time. Don't know what could be the situation with the one you're looking at. Floorplan, Price, Condition ???? all could figure into why it's been there a while. Give them a call and ask some questions. They are a very cordial dealer to work with. I have a few friends that have purchased from them in the past.
Interesting you mention air brake reading. Nothing wrong with that and a system that shouldn't be taken forgranted of. The more you know about the system the better off you are. Good luck and hope all works out.