He was on the morning drive and did mention he was "sitting in for..."
Just thinking "out loud", maybe his deal is fill in, sponsor endorsements, mobile DJ gigs, and on site remotes, or, maybe just a lark to do some air work for a week. Regardless, could be a "win-win" for both the station and Marvin. He stays in the market and does the format he is best known and the station gets the highest profile oldies guy in our market. Having the experience of running a budget-limited "local" station, that would be my plan. Make him the "face" of the station. Trade him a car and other perks. Sell sponsor endorsements and remotes.