It could be a custom font, created specifically for the game.
It looks similar to the font used for the original Apple II version, but is not the same.
I've tried using What Font is and WhatTheFont!, but no success there.
Maybe I could e-mail and ask the people who worked on the graphics/artwork (Leila Joslyn, Avril Harrison, James St. Louis).
Or maybe the programmer (Lance Groody) or Jordan Mechner knows?
It would be nice to create/have a TrueType font file (.ttf) that we can use to write custom text in the style of the original game.

(mirror)