I recently went back to my older games and incorporated the newer pieces into them. I only went as far back as Revised. At first I thought it would simply be a matter of altering the setup some but found a few more problems:
1 - In the older games, Destroyers were 3-3-2-12, same as Cruisers are now. Also, Aircraft Carriers had an attack of 1, now they have no attack value. So basically, you have to bring the costs back to the older games and you have to use the 1940 battle boards.
2 - You can’t use air or naval bases in the older games. Especially in Revised because there are a lot less sea zones. For example, with a naval base, Japan and W USA are one move away from each other.
3 - ICs and build limits also present a problem. In the older games, you simply have ICs and their build limit is based on the IPC value of the territory they are on. I don’t know how to incorporate Major and Minor ICs into the older games. I simply used the new unit values with the old IC rules.
Well, I hope this helps you. If you would like my setup changes, let me know and I can post them for you.