Brad,
If the milky appearance is coming from dull finish on the surface, it can be removed with a good cleaner/polish like "OZ". However if it is coming from the area where the finish and the wood meet, the cabinets would have to be stripped and refinished, and that is very expensive.
This is only a problem with the high gloss woodwork in the Marquis coaches, and it does affect their resale value if it is very extensive. The problem is usually caused by high humidity environments like Florida, or the Gulf Coast, so it should not be a bad problem in Arizona unless the coach came from a humid area.
Gerald