I just found an essay (sorry, in Hungarian) giving a historical overview of the meanings and political uses of Central Europe, as well as Eastern-Central Europe and Eastern Europe. It appears that all the meaning variations I named for post-1990 existed earlier: ECE appeared in German schemes for Central European hegemony, an Eastern Europe West of Russia-Belarus-Ukraine appeared in between-world-wars Polish-Czech nationalist historiography. The article also claims that (all of) Germany was counted into CE from the emergence of the term in the late 18th century.

On the Central Europe Debate, this article both connects and separates it from a debate among historians about Central Europe as separate cultural region, which started in the seventies.. E.g. the intellectuals were really for the re-joining of the two sides of the Iron Curtain, not an identity separate also from the West (but a purer essence of it if we look at Kundera).

Hm, maybe I should write a diary.

Or maybe you are already better-read for that :-)

At any rate, thanks for sending me on this search.

_{*Lunatic*, n.
One whose delusions are out of fashion.}