A more or less there version of the short lived Class 17 Clayton. As the loco is more or less a mirror image, print 2 of most of the parts.

Bogies are designed around the Fosworks units with top hat bearings.

Handrails etc. 1mm brass wire.

There is adequate room inside for directional lights (3mm bicolour), headcode lights (use Fox transfers), and sound.

I would construct the two bonnet sections using self tapping screws, before joining the two halves together.