Mix the oil, salt, cumin, oregano, black pepper, red pepper, garlic, lime juice and orange juice in a small bowl. Make small slits in the pork with a paring knife and rub the pork liberally all over with the oil/spice mixture. Place the pork in a slow cooker and top with the remaining juices from the bowl. Cover and cook on low until tender, flipping once halfway through, about 6 hours.
Remove from the slow cooker and let cool slightly. With two large serving forks, shred the pork into thick chunks. Set the pork back into the slow cooker and keep warm in the cooking liquid.
Slice the roll open and spread both sides liberally with mustard. Layer on the Swiss, pulled pork, pickles, onions and sprinkle with cilantro. Brush melted butter over both sides of sandwiches. Using a Panini machine, press the sandwiches until the bread is golden brown, and the cheese is melted, about 3-5 minutes.
Cut the sandwich in half and serve with your favorite potato chips.