The small exterior panels for the front and rear are slipped in place next. Eventually, a small drop of glue will be used to hold them permanently. It takes longer to tell about this whole procedure than to do it. I noticed the windows seem to beg for interiors and lighting in the structures. I will have to look into this, probably with LED lighting.
Finally, I laid the double track for the main lines on top of the piers. I think I'd better order elevated viaduct sections to go up there.