What cracked me up about Marv's role in the Whitner negotiations was that he called Whitner two times (at least) to say "gee, you really should get in here", like he was a neutral third party. It's like buying a new car and the owner of the dealership comes in and tells you that, gee, the salesman is giving you a good deal and you really should take it.
Of course Whitner says "when Marv talks, you listen" because he has to now that he's signed, but when Whitner hung up the phone with Marv and called his agent, I'm sure they had some good laughs about that.