A lot of really good pictures there - and your tales of chasing trains when things go adrift are very readable!

One tiny hint, that you may or may not accept - in one or two shots you have used the zoom at its wider end, in order to squeeze all of the loco into the shot. This can produce a bit of a caricature, as in the shot of 2473 on the Bluebell. Better to stand further back and use the zoom on a slightly longer setting, where the "barrel distortion" reduces.