I had a reply from Colin at Gibsons. It looks like I'll have to dismantle the loco to see if the axles would match up with the Gibson wheels. If so, I'll end up with two BWT's. I'm hoping someone else has had one apart and can give me details of the axle diameters and what type and size the ends are. I have had this one apart, but it was back when it wasn't very old. I'd all ready sent one back to Kernow, faulty and this one had a pick up stuck in the spoke of one of the pony wheels. I had to cut the brake gear to get the keeper plate off and I really don't fancy doing it again unless it's to replace the wheels.