The following recipe is not one that I have made myself; however, it sounded very similar to the one you requested. It comes from a small cookbook that was handed out by realtors and dates to the late 70s – Port Pourri Recipes – Rich Port Realtor.
7-UP SALAD
2 – 3 ounce boxes lemon gelatin
2 cups hot water
2 cups 7-Up
1 can drained crushed pineapple (keep juice)
1 cup small marshmallows
1 can drained mandarin oranges
1 cup pineapple juice
1 egg, beaten
1 cup sugar
1 heaping tablespoon flour
1 envelope Dream Whip
1/2 cup chopped nuts
Dissolve gelatin in water. Add 7-Up, pineapple, marshmallows and oranges. Pour into 9×13 inch pan or large dish and refrigerate until firm. Heat juice, egg, sugar and flour until thick, then refrigerate. Prepare Dream Whip as directed, chill, and blend with chilled pineapple juice mixture. Spread over gelatin, sprinkle with nuts.