So this arrived.

The Orient Express was a long distance rail service that began in 1883 carrying passengers across Europe from London to Constantinople (now Istanbul).
Over the years route changed several times over the years and eventually the terminus changed from Istanbul to Bucharest to Vienna.
The route finally disappeared from the European Railway Timetable in December 2009.

My plan (at the moment) is to follow the London, Paris, Strasbourg, Munich, Budapest, Bucharest route to Istanbul and then return via Sofia, Belgrade and Venice.
And if there's time make a few detours along the way.