Had Germany defeated France, Italy, and the Austro-Fascists in a 1938 Anschluss War, what would have the post-war boundaries have been?
I exclude Britain because I get the vibe that Britain probably wasn't willing to go to war over Austria. Even before Stresa broke down, the British were having their own negotiations about lifting the constrains on the German Navy. Britain didn't seem too interested in going against Germany - especially when the demands were still considered "reasonable" by folks in the UK.
Alsace-Lorraine and South Tyrol seem like expected German aims. During WW2 though the Germans annexed Trentino, Trieste-Istria, and Friuli and looked at pushing the French border back to 1648.