How many movies have Gordon Gurnee and Marshall Schlom collaborated on?

They have worked on 2 movies together! Their first movie together was It's a Mad, Mad, Mad, Mad World (1963) and was their highest rated movie together. They have not worked together since Hurry Sundown (1967).

Hurry Sundown (1967)

Crew
Assistant Art Director
Crew
Script Supervisor

It's a Mad, Mad, Mad, Mad World (1963)

Crew
Art Direction
Crew
Script Supervisor