This is much later than your estimate, but I'll give it a try.
Scavenger Hunt (1979)
Wikipedia synopsis:
Milton Parker (Vincent Price), an elderly and eccentric game inventor, dies after losing a video game with his seductive nurse (Carol Wayne). Following his funeral, Parker's greedy and estranged relatives show up at his mansion for the reading of his will. They learn from lawyer Charles Bernstein (Robert Morley) that the winner of an elaborate scavenger hunt will inherit his $200 million estate. The (potential) beneficiaries form five teams and get involved in various misadventures.
Each group is given five lists containing clues to acquire 100 items with various point values ranging from five to 100 points. The items are to be acquired by any means necessary, with the exception of being purchased. They are to be placed in five different pens on the grounds of the estate. The winner of the scavenger hunt will be the person or team to acquire the most points by 5 p.m. that day.
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Scavenger Hunt - Wikipedia, the free encyclopedia