A CHEESEBOX UNDER THE DOUBLE EAGLE. In the course of researching the Confederate commerce raiders, I learned of a noteworthy preservation effort on the banks of the Donau.
The Dual Monarchy commissioned some river monitors in the 1870s, and the hull of one, Leitha, is the focus of a preservation effort in Budapest. (There is at least one of the Hungarian railroad system's streamlined Suburban Tanks in preservation ... must consider another trip that way.)
The preservation effort envisions restoring it as an Ericsson Battery, with a little help from its friends. (There appears to be a way to send Yankee greenbacks.)