Split the baguettes horizontally through the center but not all the way through the crust on the other side. Leave a hinge if you can. Cut each baguette in half crosswise, resulting in four pieces total.
Divide the tuna, eggs, lettuce, tomato, pepper, and olives among the four sandwiches.
Drizzle with vinaigrette. Serve immediately.
Promptly store leftovers in an airtight container in the refrigerator, for up to 4 days.Nutritional values are approximate and based on 1 sandwich.