Prepare grill with hot coals around sides and drip pan in center. Rinse and prepare turkey. Grate 1 T. orange zest. Halve orange and squeeze 1/4 C. juice. Combine zest, juice, sugar, seasoning, Barbecue Paste and half of the onions. Carefully loosen skin from turkey breast. Spread orange mixture under skin. Place orange halves and rest of onions in turkey cavity. Sprinkle outside of bird with more Mansmith’s Poultry Seasoning. Place turkey on grill rack over drip pan. Grill covered for about 3 hours or until meat thermometer reaches 175. Add briquettes to maintain heat as needed. Let rest 15 minutes before carving.