Righto, I've ordered some adapters from Nigel's website, and some worm gears too, so I can start mounting it up soon (thanks for the recommendation Stephen)
Here's the progress to date on 'Bill'.
I've infilled the front of the cab with styrene cut to size, and cut the cab windows out. The firebox top is formed from a piece of pre-curved plastic, and more styrene strip was used for the bunker extensions. It's reinforced on the back with more strip.
Here it is part way through filling and sanding. The holes in the running plate (that were left over from cutting out the 'skirt' under the saddle tank) have been filled in with more styrene strip (big flat'uns).