Our Mountaineer has been ailing for some time - although at least, unlike the real one, it was still in service.
Its progress was very erratic, both in starting and when on the run, until finally it expired in a cloud of smelly smoke.
The problem clearly lay with the motor, but Himself was reluctant to break up the spare Arnold chassis we have in stock for a motor transplant.
Instead he was even more ambitious and found a way to extract the the commutator from another, even older, chassis and install it into the motor housing of the one under our operational Alco.
We gave it a test at the weekend and it performs very well now.
It does still irk me that it's the only locomotive we have left in our fleet with an inaccurate chassis, and I retain an ambition to get him to have a go at fitting a Farish O8 chassis into a spare body kit I obtained for just this purpose.
The trouble is there's always something else in the build queue ahead of it.
I suppose at least that's prototypical......