I have a 462 Merchant Navy Class that I have tested the set track points with and hasn’t had any trouble.
I have the track laid out loose on the table top for testing with.
I have access to all sides so the width isn’t a problem.
the tunnel I wanted in to split the scene and give the affect that the trains dont run the same scenery, similar to what they do with show layouts and have a fiddle yard round the back.
era I’m planning to be around 4/5. But that isn’t strictly set in stone. I enjoy all steam locomotives.
I am considering a turn table with an engine shed close by.
thanks all for the feedback, I’ll have a tinker with the layout with some feedback from you all.