One day, I'll learn.
I noticed before painting that I still hadn't cut and fit the remaining holes for the baseboard to pass through at either end of the modules. You guessed it, that's where today went.
The room the layout is going to live in for the time being requires the left-hand reverse loop to run into a wardrobe and out again, before entering the fiddle yard. This wardrobe also currently prevents the cement siding from protruding out of the module for the time being. At the time of taking the photo below, I was still testing clearances for the siding off the main. Later today I cut the hole for the cement siding to continue out of the module at a later date. I figured it would be much harder to do once the track was down.
The next photo comes to the point of this post. The holes for the track and baseboard required a clearance of about 8cm x 5cm. Once I had the baseboard through the right-hand side of the backboard, I found I had forgotten to account for clearances on the vehicles traversing the section. Pictured is a silver LLV, and previously I had a KLV running through. I'm yet to get to testing my longest vehicle - a Tulloch Railcar - but I'm confident the gap is now at the right size.
The most time-consuming part was getting the holes level to accept the baseboard, and in this respect the Auscision KLV was brilliant; the wagon's free-rolling gave me a more relevant indication of progress than using the spirit level alone. Although the gap is quite long, this area will be covered by a hill and road overbridge.
Now to put down the tools and entertain for a weekend.