This is a 1965 recipe for Boston Cream Pie, but it lacks the chocolate glaze. I don't know if it's like the one you're looking for, though. It comes from Woman's Day Encyclopedia of Cookery:
Cake:
1/2 cup butter
1 cup sugar
2 eggs, beaten
2 cups sifted cake flour
2 teaspoons baking powder
1/2 teaspoon salt
2/3 cup milk
Filling:
1/3 cup granulated sugar
2 1/2 tablespoons all purpose flour
1/8 teaspoon salt
1 cup milk
1 egg, beaten
1/2 teaspoon vanilla extract
Cake:
Preheat oven to 375° F.
Beat butter and sugar together.
Add eggs and mix well.
Sift dry ingredients together.
Add dry ingredients and milk alternately to the egg mixture.
Pour into 2 greased 8" round cake pans.
Bake for 20 minutes.
Remove from pans and cool on cake racks.
Filling:
Combine sugar, flour and salt in a small saucepan.
Add 1/4 cup milk and stir until smooth.
Add remaining milk and cook over low heat until thickened.
Add milk mixture to egg.
Return to saucepan and cook for 2 minutes.
Add vanilla and cool.
Assembly:
Spread cooled filling over bottom layer of cake.
Top with remaining layer.
Sprinkle with confectioner's sugar or coconut.
This is the only 1960s recipe I've found so far, and I don't think it's particularly authentic. If it's not what you want, I'll keep looking.
If you first had the cake in a Chinese restaurant, it's probable that it wasn't made on-premises. Was there any sort of a bakery nearby?
You may also want to try one of these other recipes, which are made with cornstarch and so will have a less cloudy filling.
Boston Cream Pie
Boston Cream Pie
Boston Cream Pie
I've not found any recipe that uses gelatin in the filling.