My P&S is a Nikon Lite Touch. My other option would be either a FM2 or a Fuji 645.
Our train journey, the bit I'm really looking forward to, has stop overs in those cities for only a few hours. We won't have time to explore. I remember Erich Hartmann used an XA for his 'Train Journey Through France' - travelling light and being inconspicuous.
This is really a family trip - we're taking our two year old to see his Romanian family for the first time - there will be lots of chatting & eating and group photos, maybe some nice candid shots. I thought the Nikon Lite Touch with the 28mm lens would be good for that and also the cramped interior of a train.