Doubleeagle sleeper parts. Where to get them?

Hi all. I have a Doubleeagle sleeper that I need a few parts and pieces for. I think the roof vents are basic camper stuff, but there is an air filter on top above the fridge that has a cover over it to keep water out. The cover is broken beyond repair. Might someone here know where to get these sort of parts now?

Also, did Doubleeagle use a proprietary boot to the cab, or did they use the truck brand boot for each sleeper?

Thanks.