Can't wait for the Key Limes, try oranges

I have been waiting patiently for the Key Limes that hang over my property line from the tree next door to ripen. I have permission to harvest all that I want from the portion of the tree that hangs into my yard...the same goes for the line-hugging lemon tree.
The beautiful little green beauties were still not ripe when I went out to check this morning and my craving for a Key Lime Pie was pretty intense so I wandered back to my yard where the orange tree his hanging heavy with fruit.
Did you know that Key Lime Pie came into being at a time when modern refrigeration was not commonplace in the Florida Keys (used in many cakes and pies at the time) was a rare commodity. The pies were not baked because the acid in the limes reacted with the condensed milk to solidify the filling. It was the perfect combination of ingredients for the tropical paradise outpost. I bake mine because my family has this strange need to have their eggs cooked before eating them.
Is citrus interchangable in a sweet custardy pie like this? Key Lime Pie? Lemon Meringue Pie? Could there be an Orange Meringue Pie?
I had never had such a thing, but I imagined it was worth a try.
A sweet citrusy success resulted that's not quite what I had in mind, but certainly delicious. Sort of like a creamsickle in a crust.

Orange Creamsickle Pie

Crust
20 graham crackers, crushed into light crumbs
1 tablespoon butter
2 tablespoons sugar
Pie
4 large or extra large egg yolks
1 14 ounce can sweetened condensed milk
1/2 cup freshly squeezed orange juice
2 teaspoons grated orange peel, orange portion only
Meringue
4 egg whites
2 tablespoon sugar

• Mix the ingredients and press them into a 9 inch pie plate. Bake in a preheated 350 degree oven for 10 - 12 minutes until lightly browned. Place on a rack to cool.
• Beat the egg yolks until they are thick and light yellow, don't over mix.
• Turn the mixer off and add the sweetened condensed milk and mix on low.
• Mix in half of the orange juice. Once the juice is mixed in, add the other half of the juice and the zest, continue to mix for just a few seconds more.
• Pour the mixture into the pie shell and bake at 350 degrees for 12 minutes to set.
• While the pie is baking, whip the egg into medium-soft peaks. Beat in 8 tablespoons white sugar. Continue to beat until egg whites are glossy and hold a firm peak.
• Spoon over the filling and bake for another 5 minutes until the tips of the covering are browned.

Vegetarian