Joe, I'm not sure Barbara Mandrell had a Prevost, but you can buy her Eagle.
http://www.staleycoach.com/49383%20%...ar%20Coach.htm

I believe it was converted by Hemphill Brothers that remains the big daddy of entertainer coach conversions. Wade Staley is a walking history book of early entertainers back when the Calhoun Brothers started. They are still in business as Florida Coach. Another guy that seems to know the old stuff is Michael Gibson of Imperial Coach outside of Dayton, OH. I know Prevost painted a lot of motorhomes, but didn't realize they did a conversion. I think Liberty may be the first, if not one of the first, to convert a Prevost to a motorhome.