Maybe go "retro party"?
Cubes of cheese, Pineapple and silverskin onion on sticks
Coleslaw, potato salad, beetroot salad, sauerkraut
Crisps in "fancy" flavours or types - corn chips, bugles, frazzles etc
Dips
"Crudités" - carrot batons, sliced peppers, cucumber, celery
"70's buffet" stuff - mini versions if available - pork pies, sausage rolls, quiche, scotch eggs, even tarts or vol au vents
Retro "plain" sandwiches - cheese and branston, cucumber, ham and mustard, egg mayo, prawn cocktail
Just a few ideas