Think they may go to Washington DC first and find the medallion that will lead them to Dover Castle and the White Cliffs of Dover. In Paris they will be looking in the Catacombs easily reached by Metro at the Denfert-Rochereau stop on either the Red, Blue or Green line in Montparnasse. Looks like they take a car ferry either to or from Dover. In England someone else is driving at night (note right hand wheel).
So does all this happen in one ep? Do they go to New York first and the Hall of Fame in the Bronx then across the pond to England?
In any case, if they go to Europe for several eps, then we know that the Air Force, the Southies, and the Geniuses will be in the final three since we see the Geniuses at the Star Spangled House or Ft. McHenry in Baltimore and the Air Force and Southies at the Hall of Fame in New York. That means we will lose the Fighting, Screeming Fogels, and the beautiful ones somewhere in Europe.
How does a death mask of Bonepart jive with a map of Baltimore Harbor? The seven artifacts are supposed to lead you to the key to where the treasure is hidden. Maybe it really is a death mask of the admiral who led the attach on Baltimore or perhaps Francis Scott Key who wrote the poem Star Spangled Banner.