The thing is, with that time frame, many will be eating supper from the buffet, so it increases amounts. As will alcohol. 85 people is 5/6 of 100.

Sliders of Beef Fillet, pork tenderloin and ham- about 1 ounce ready to eat meat per bun, that is 1 pound raw per 10 sliders
I would do 2 1/2 to 3 beef plus 1 each pork and ham per person

shrimp cocktail, 1 pound per 5, 1/4 cup cocktail sauce, pre portion into cups or increase to 1 pound per 4
meatballs, 1 pound per 5
pigs in blanket, 3 small per person
bite-sized baked mac and cheese, they will scarf, 4 ounces per person
deviled eggs, I do 4 1/2 dozen eggs for 100
cheese trays- 1 pound cheese per 8, 1 pound crackers per 10

I would add one or more starchy item- bruschetta, for example, or some such, or hummus and pita, or tiny potatoes, 3-4 ounces per person

fruit, see fruit tray page
veggies, see veggie tray page