Nearly a year from the last update on the Baldwin marathon, and there has been some progress.
The motion has been completed; this took about 12 hours of fiddling and fettling per side. Definitely not a "shake the box" or a beginner's kit. The loco runs very smoothly and the track holding is excellent with the springing modifications I carried out.
The plate work for the cab and bunker has been put together, and my wife is now wondering exactly where I am going to put the model when it is finished. This thing is huge, I should have stuck one of my Gn15 Bagnalls alongside it for a size comparison:

The large squares on the cutting mat are 50mm, so that should give you some idea of the model's size. Note the now traditional wife's cardigan over the chair in the background
I added some 1mm 'D' section for the cab beading in place of the flat etch supplied in the kit as I did not fancy the idea of trying to file a consistent radius on the etch:

The cab interior has been dressed up with some angle in the corners and a bit of scrap etch to represent the piece over the join between the cab front sheets:

The next little jobs (if you can call any job on this bruiser of a model little) will be to glue the boiler parts together, bolt the cab on, then make the weighshaft. I have got a small servo to operate the weighshaft to lift the radius rods, and have found that a Zimo MX644 decoder can be used to operate it. Nearly forgot that I also need to make the vacuum brake valve and extend the cab roof as I intend to finish the model as the Welsh Highland Railway's 590.
Now all I need to do is find some time in between work and all those "important" jobs that need doing in the garden
