Got to this thread via Googling for "73766,347" in hopes of finding out what it was.
After a bit more poking around, I think I've found it (and so I thought I'd post it here, to help future searchers):
It's the CompuServe address of Matt Gruson, one of the creators of the game.
In the mid-90s, CompuServe user IDs
fit that numerical pattern, and there's a direct reference to it being his in
the README for some shareware he worked on.
A web search shows references to this number in "Rex Nebular and the Cosmic Gender Bender" and a config file of "Ripley's Believe It or Not!: The Riddle of Master Lu". Sure enough,
he worked on both of those.
So, yeah, it's an Easter egg--"here's contact info for one of the developers."