Hi Dudley,
I've had a look for this issue of BRM but cannot find it. My rubbish filing system! I can show you some close up shots of my wagons. All of these are built from PS104 hopper kits and are basically out of the box without additional parts, even down to the transfers. The only additional consumables needed are Humbrol Precision Poly cement, rattle can grey primer, rattle can matt black, Railmatch freight stock rail grey, Railmatch frame dirt and a whole host of weathering powders and paints. The main adjustment I make to the kit are to the coupling hooks which need shortening so that they fit between the headstock and the inner frame.
All these wagons are modelled from Paul Barletts wagon website, just search for HTO. I built the bodies first leaving them to set overnight and then spraying them all over with grey primer. While that is drying I built the chassis separately on a piece of plate glass so that the frame doesn't twist, which will cause the wagon too wobble once finished. When the chassis is set I lightly oiled the axle boxes and taped the wheel treads, spraying it with matt black paint before the buffers and coupling hooks are fitted. The bodies are now sprayed freight stock grey and married to the body.
I hope this helps?
Vin