I just popped in the DVD to see two characters I thought might be MM. The singer in the show that young Vito and Genco go to when Genco wants Vito to meet his heart-throb. Wasn't him. Then I thought maybe its the girl's father, the owner of the theatre. Not him either. Not even Abbandando the grocer.

I think it's one of Mike's assasins they fished of the creek in Tahoe.