On this site is a big collection of maps including many older ones:
The Iron Blitz download includes some scenarios similar to Operation Unthinkable:
These are not compatible with latest version of TripleA
-Use older version of TripleA
-Update them yourselves if you know how
-Ask Roger Cooper to update them:
-Create your own Mod in any of the existing maps.
Modding is not very hard. Especially if you're only changing unit placement, territory ownership and Alliances. NWO mod for this scenario would be cool.