G'day, Gary!
From what I understand, Hasbro doesn't actually have the rights to all the old AH games. The situation is a bit... confused. It certainly confuses me. There are a few old AH games that have been republished or soon will be...
ASL is licensed by Hasbro to Multi-Man Publishing
Titan's rights have been picked up by Valley Games; they're doing a reprint later this year or early in 2008. They're also doing a reprint of
The Republic of Rome
Dune's rights have been gained by Fantasy Flight Games, along with
Cosmic Encounter (the latter not a AH game, but a classic). CE will be reprinted first, then Dune (and later
Borderlands). Unfortunately, the actual rights to do a "Dune" game are not available, but the mechanics will be done in a new setting...
Oh, and there's a recent discussion about your variant to Rail Baron on Boardgamegeek...
http://www.boardgamegeek.com/thread/168817
Cheers!