StewL wrote:Diverge away Thrall

Indeed
If I had a £ - pound - for every time I've read stories of N American researchers being unable to find the record of their ancestors' immigration to the US on the basis of the "obvious" port of departure, I'd have a good few more pounds in the bank
The fundamental point to realise here, - there's another recent thread here in relation to UK to Australia, - is that it's the final port of departure that more often appears in the indexes.
Virtually every country's emigrants at some time or another travelled via English ports, including many Scots who travelled on a boat that left the Clyde but then called in at Liverpool or Belfast, or travelled by a small ship or rail to such "departure" ports.
Many central Europeans travelled via Copenhagen or Hamburg and other German ports. (Have a Google for the SS Norge disaster in 1905 which predated the RMS Titanic, and, but for which, the Titanic wouldn't have had the number of lifeboats that it did, even if that number was still inadequate.)
Have a look at the map of Europe to work out the possible ports of departure, taking into account local possible travel via ferry and rail, never mind even long distance travel by rail !!, and examples such as the above, - e.g. from central Europe to a Channel port, across to England by channel ferry, train to Liverpool, and, finally, the ship to N America !!
David