I had planned to post an update last night but ran out of steam.
The horse box now has it's roof on and I spent most of yesterday beefing up the rather flimsy brakes. By good fortune I bought a lot of etched kettle related spares from Mike Cole (Resseldar) and among them there were 16 etched brake shoes in Nickel which are a perfect fit (8 for this box and 8 for the Midland box should I need them). Once they were soldered to the brake shoes in the kit, I used scrap etch to strengthen the arms. I have also got one of the step boards on and again used scrap etch to strengthen the support straps for the lower step boards.
I have also attached the brake cylinder and cross shaft - rather stupidly not adding rocking arm for the brake rods despite adding the one for the cylinder :-[
No photo's of the underframe fittings yet but hopefully sometime this week[/attach]