Interesting thread and wonder how you have got on, also no hint of a gauge war bun fight which makes a nice change. Our layout is P4 but I am lucky, I just paint stuff the other person I work with does all the building and he enjoys making track the weirdo. We stick with C & L chairs but I have seen those fold up brass ones. Lovely detail but very fiddly and I would wonder if you could tell the difference. Would also reiterate what has been said, diesel/electric will be easier to convert simply because there are less wheels for a start no trucks and no cranks/pistons to mess about with. Also as said yes it's still 4mm scale so figures buildings etc the same. Opens up the wider question though as to what finescale actually is. Ask 5 different people and you will get 5 different answers with none of them being wrong - with the exception of just a conversion to P4 or EM isn't it - it's a much more nebulous thing that involves everything visible on the layout.