It looks like Grandma was into the whole copy cat recipe thing. I am basically posting the recipes as I pull them out of the box. The last few have all been restaurant favorites. This one is no different. Frisch is Frisch's Big Boy restaurant, the local Big Boy franchise. I believe she got the recipe from my sister who worked there in the seventies.
Frisch Strawberry Pie
1 1/2 cups sugar
1 1/2 cup water
1 sm package strawberry jello
1 1/4 qt strawberries
Mix sugar, cornstarch, salt and water. Cook til thick and clear. Add jello and dissolve. Cool til thick. Pour over berries in crust.
I am pretty sure you can use this one as written. I don't know of any change in the size of the gelatin packages and I'm not sure it would be critical if there were slight variations. The 1.25 quarts of berries is an odd number, but I am sure that is what made a heaping pile in grandma's pie plate. The berries were washed and hulled but not cut into pieces.
This pie used to be one of my favorites. We would only get it in the early summer when the berries were ripe. This is a good pie because the berries are fresh and whole and not cooked. It does need to be eaten in a day or two as the crust will get soggy.