But the Rail tour is several days and starts near where you get off the plane/ferry or has good transport links to them. We will travel if the perceived value is worth it, but a long trip for a single day on a historic line does not equate to the same Which is why I said " It's not that those in the UK are not interested in Irish historic railways "
You also mentioned Steam trips abroad, E.g. Italy
So yes Italians = Obviously
Austrians, Germans Czechs , OK comparatively close and drivable but continental rail fares are so cheap why bother.
Aussies and Poms, Like I said for a longer rail tour event they will travel (I presume this was an organised event over several days travel) The "value" is there.
And Italy is also a holiday destination so some may stay on at the end.
The point I was trying to make was particularly about the historic lines and museums in Ireland being compared to similar in the UK mainland.