How come Disney never turned this into a franchise by making one or two more sequels? It's one of my favorites along with Warren Beatty's version of Dick Tracy. I read on a few websites that sequels were planned for both movies but they never materialized. Both movies would have made interesting attractions at Disneyland and I do remember back in 1991, that one of the rides that was originally supposed to go in DCA was a ride based on Dick Tracy.
PS: I just saw The Aviator today which is set in approximately the same time period as the above mentioned movies. Pretty good movie and the experience is enhanced if you've seen or been in the real Spruce Goose! (Saw the SG when it was still in Long Beach back in 1985 - want to see it again next time I drive down to Oregon)