Can't help you with 'gearhead' sights.
All I remember is Diamond Head and King Kamehameha.
Well I remember other things too...but not sightseeing.
The zoo, the beach, school, pineapple fields, a lot of flattened frogs, someone's entrails after a shark got done.
I was in Hawaii when I was six. 1959. Was there when it became a state.
Dad was baton major in a parade (Army band).
Oh yeah...always in flip-flops, shorts, and Hawaiian shirt. Sis and Mom in a moo-moo.
Fun time.