Preheat oven to 350°F. Thoroughly grease two 13x9 baking dishes. Set aside.
Spread sausage evenly in the bottom of a half sheet pan. Pat down and set aside.
Scramble eggs, evaporated milk and seasoned salt in a bowl, then pour into the two 13x9 well greased baking dishes. Bake eggs and sausage at 350F for 18-20 minutes or until the eggs are set and the sausage is done (170F). Cover the eggs with a sheet of parchment if necessary to keep the tops from getting brown.
While sausage and eggs are cooking, cut rolls in half lengthwise (keeping in a sheet if possible).
When done, remove the sausage and eggs from oven (keep oven on), remove sausage from the pan and cut sausage into 40 patties (8 rows by 5 rows). Pour out sausage grease and wipe down the half baking sheet.
Place bottom half of rolls in the half sheet baking pan. Place 1 sausage patty on each roll bottom. Slice each dish of eggs into 20 pieces. Place 1 egg slice on each sausage patty.
Top eggs with 1 quarter slice of Monterey Jack cheese and 1 quarter slice of American cheese. Carefully place top half of buns on top.
Bake at 350 degrees F for 15-20 minutes or until cheese is bubbly and melted. Serve hot.