Just a quick one, are you including the sanders fitted to number 1 axle? They've been fitted for three years now, and follow a similar form to the 150/153 units. The sand hopper is fitted on the under frame, under the second mans side of the cab along with the test switch and a box for the sanding ep solenoid valve, with one flexible pipe bolting straight to the lifeguard by no1 wheel and the other going across the skid plate under the fire bottles, to emerge at roughly the same position on no4 wheel. It's visible on 611, second page of the brochure and fitted to all west fleet 14x after an incident of low adhesion at Exeter.
http://www.porterbrook.co.uk/downloads/brochures/14x%20Brochure.pdf