Preheat oven to 400 F. Rub potatoes with oil & place on a baking sheet. Bake about an hour or until soft to the touch. Let stand until cool enough to handle. Cut a slice off the top of each potato lengthwise. Scoop out pulp, leaving a thin shell. Place pulp in a large bowl & mash.
In a small skillet, fry bacon until crisp. Drain on a paper towel & crumble. Saute green onions in 1/4 cup butter until tender. In a small dish, stir Ranch dressing powder (mix) into sour cream & add to potato pulp along with milk, salt & pepper. Fold in half of the cheese. Divide mixture between potato shells & drizzle with remaining butter. Place baking pan on BBQ where the heat is lower & warm potatoes through while shrimp is cooking.
In a foil BBQ pan, Gently combine shrimp, olive oil, garlic, oregano, basil, parmigiana-reggiano, salt & pepper. Roast until pink, firm & cooked through, about 6-8 minutes.
On each serving plate, place a stuffed potato, top with shrimp & garnish with crumbled bacon & remaining cheese.