FYI - you "can" take the top apart, but it is less than a joy to reassemble. I have pics of how if you need them.
I sure do wish that Boye had made these back in the 1870-80's Ahhh to dream.....
... and as a side note. I made a permanent mold of the pointer on top and cast a pewter copy for a friend. If anyone else needs one, let me know. (no charge, just trying to help)