I'm a great fan of the WR5 so I think you've done a great build. I have an SM32 WR5 which I built in metal/tin and using mamod wheels (yes slightly oversize). Not quite as much detail as yours however I managed to get a lipo and remote control in the battery box. Like you I have the motor and gearbox in the chassis. I'm considering building one for 5" gauge and the Tilston plans you mentioned would be incredibly useful but I haven't been able to make contact either. I'll be interested to see your WR5 painted/weathered or whatever you plan to do with it next. Good luck.