Not sure if you meant the coach has had a lot of checks done already or it needs to be checked.
In both cases it is buyer beware so most here will recommend a thorough check over by a knowledgeable person, or paid expert to support your purchasing decision.
There are a few people that are ex Country Coach staff that fall in the "paid expert" category, and may be available depending on location of coach.
It is worth the expense when you are considering a 75-150K investment, IMHO.
Hope this helps,
EDIT: just crossed my mind that you may be referring to "paint checking" in the dark colors. This is common in some units in that era, as the fibreglass curing in the hot sunshine after painting created some flaws in the painted surface. Can't remember the correct term used....