Yep, what Roux said. Doesn't matter which roll is first as long as you indicate which one is History and which one is Occult. They're two skill checks for different things, not two checks on the same thing. The Occult roll was for the symbols on the inside of the box. Since no one has yet passed the History check I'm not going to tell you what it's for!
All skill checks in Call of Cthulhu are 1d100. In fact most rolls are percentiles other than things like damage. If I don't specify, assume it's 1d100. As I mentioned in one of my posts in the other thread, too, make a mark or indication of some kind on your character sheet if you pass a skill check (except for this History roll, heh). Skills marked like that have a chance to be increased at the end of the adventure.
The detestable pounding and piping whereunto dance slowly, awkwardly, and absurdly the gigantic, tenebrous ultimate gods -- the blind, voiceless, mindless gargoyles whose soul is Nyarlathotep.