Place the can of evaporated milk, electric mixer beaters and a metal mixing bowl in the refrigerator. Let chill for at least 4 hours.Wait until at least 2 1/2 hours has passed before proceeding to next step.
Place dry jell-o mix and sugar in a large bowl. Add boiling water and stir until sugar is dissolved. Stir in lemon juice.Refrigerate for 1 1/2 hours.
In a medium bowl stir together vanilla wafer crumbs and melted butter. Set aside 3 tablespoons to sprinkle on top and press the rest into the bottom of a greased 9x13-inch baking dish.Refrigerate until needed.
Open can of evaporated milk and pour into the chilled mixing bowl. Use electric mixer to beat until soft peaks form.
Use electric mixer to beat Jell-o mixture for a few seconds to make sure it is smooth and even consistency. Fold in the evaporated milk.
Spread mixture over crust. Sprinkle with reserved crumbs.Cover and refrigerate for at least 4 hours.