I dismantled the baseboards from the middle of the living room and erected them in a more out-of-the-way corner. This is still not an ideal location because other furniture has been displaced and I have nowhere to bring in my huge specimen Strelitzia plant for the winter - but we'll deal with that when the time comes.

In the meantime, having the layout more permanently set up has meant I've been able to push on with laying cork trackbed and actually laying some track!

This was the track plan:

I used a curved point (green) on entry to the back sidings because during planning I found that it caused less deviation from the curve radius than a small left. More on this later...
I've left on some of the construction lines and you can see that I briefly considered transition curves (orange) between the straights and curves but since the layout is for running-in and testing locos I decided it wasn't worth the extra complexity.

The trackwork is all Peco code 75. I drilled holes under all the point tiebars in case I decide motorise them one day and brought all the frog dropper wires through the baseboard as well. (I didn't snip any bonding wires under the points before I glued them down - this may prove to be an error in the future.)
All the track of the main circuits and points leading to sidings was pinned in place temporarily then glued down with PVA and the rails were soldered to copperclad strips on either side of the baseboard joints.

Every section of track has dropper wires waiting to be connected but I realised that if I just wired up one or two pairs of droppers I could actually run a loco (relying on the joiners alone to supply power around the entire layout).
Here is the glorious moment when the first train ran:

Since I took that video I have cut the rails at either end of the bridge, lifted it out, put it back with it's own power feed and the Barclay still runs smoothly across the joints with a satisfyingly solid-sounding "click-click". It's a relief to know that the combined board alignment and copperclad rail alignment do actually hold everything accurately in line!

P.S. 40 years ago I used to cut track with a junior hacksaw and it was always a painful experience, in every sense. Now I have a Dremel equipped with a metal cutting disc - Deep Joy! ;-)