I'd have guessed maybe Marine Airrrr, possibly a Vector Compact. This would be from before Dometic started buying everybody. Sometimes you can puzzle it out by looking at the control panel and working backwards from there. Some search terms for control panels are: Passport, Passport II, Elite, SMX...
In 2006, and if it's a Vector Comapct AC, then I''d guess it wold be paired with Passport II or Elite controls.
Just guessing, though...
South River, Chesapeake Bay