Omaha, Bon jour. I'm touring Central Europe and the Danube-Rhine from late-Sept so I googled where these sites are. Can't make Austerlitz (we're going to Prague via Cesky-Krumlov rather than Brno) but my wife may let me see Wagram, Aspern-Essling und the Armoury/Museum. I've dropped it into the mix of things to consider.
Have a great day, Frank
From the other Austria, the one WITH kangaroos