I am also discovering some wonderful gems in that IRRS flickr site there is fabulous one of a H van 18828 in green with Vacuum brakes with sliding doors by Gerard McGowan , which like you I had read about but never seen picture of one . Many thanks to Ciaran Cooney of the IRRS for painstakingly taking the time to scan these pictures , while some of them are just ordinary rolling stock photos and would not appeal to many they provide a wealth of information for the modeller .