Family Recipe Friday - Blackberry Meringue Custard

This recipe is special because it's one of a few I have in my Granny's handwriting.  (A transcription is included below.)  Unfortunately I can't remember if my Granny Conley was a good cook or not, but I assume she was because her sister, Violet, certainly was and my mother most definitely was.  I do not remember anyone making this custard so it isn't a recipe that has been handed down from one generation to the next, and I'll admit I have not tried making it, but perhaps I will one day.
The trick for me is to read between the lines of written recipes.  The good cooks in my family often didn't use recipes and when they tried to write one down, things were often left out or assumed.  Since I have not tried this one, try at your own risk...and let me know how it turns out.
One example I still laugh about is trying to follow my mother's recipe for divinity.  I stopped where her recipe stopped.  I poured the golden liquid into a coffee can and when it hardened offered it to a friend as a door stop.  When I told my mother about it, she said as many times as I'd been in the kitchen with her when she made it, she thought I would know to.... whatever step(s) were left out.

Transcription:
4 Tablespoons corn starch
3/4 cup sugar
2 eggs
1/4 teaspoon salt
2 cups blackberry juice
1 cup drained berries

Combine starch, 1/2 cup sugar 1/8 teaspoon salt and well beaten egg yolks.
Heat juice to boiling. Pour slowly in first mixture. Cook until thick.
Beat egg whites until stiff.
Add remaining salt and sugar.
Sprinkle berries over custard and meringue.