Berry Patriotic Trifle

I've been making this for the Fourth of July since college.  I've liberally modified the recipe which I originally got from here to better fit our preferences.  I love it with the raspberries as in the original recipe but my girls prefer strawberries and they do make it look more patriotic.

Ingredients
1 (14 oz.) can Eagle Brand® Sweetened Condensed Milk
1-2 tablespoons of fresh squeezed lemon juice (about 1/2 a lemon)
1 (4-serving size) package instant lemon flavor pudding mix
1 1/2 cups milk
1/2 cup sour cream
2 (8 oz.) containers of lite cool whip
1 (10 3/4 oz.) loaf frozen pound cake
3 pints of fresh blueberries
2 pounds (or 2 quarts) of fresh strawberries, sliced

Instructions
1.  With a fork or potato masher, smash about 1/2 a pint (about 1/2 cup) of blueberries in a small mixing bowl.  Stir in 2 tablespoons of sweetened condensed milk and 1-2 tablespoons of fresh squeezed lemon juice.
2.  Halve the pound cake horizontally.  Then cut lengthwise into 4 strips; cut crosswise into 1-inch-thick pieces making 1-inch cubes.  Lightly toss the pound cake cubes in the smashed blueberry mixture until lightly coated (I found this easiest to do using about a quarter of the pound cake at a time).  Set aside.
3.  In a large mixing bowl combine the lemon pudding, milk, and remaining sweetened condensed milk with a wire whisk.  Add sour cream.  Let chill 5 minutes.  Then fold in cool whip one container at a time.  Put back into the fridge to chill while you prep berries.
4.  In a trifle dish layer half of the pound cake pieces.  The add the next layer of the lemon cream pudding.  Next add a thick layer of blueberries followed by more cream.  Then make another layer with the remaining pound cake pieces followed by a cream and then strawberry layer.  The on top add the remaining cream and berries.  (When you're finished the layers should be: cake, cream, blueberry, cream, cake, cream, strawberry, cream, topped with berries).
5.  Cover and chill at least 2 hours before serving.