Thanks gentlemen, so it's, 'Gee up, whoa back' then. I agree about the oversize boiler, it looks like a six foot bloke with size 3 shoes!
I will follow up the Dairymaid lead thank you, I don't know much about that engine.
I'm just dipping my toe in the 2&1/2" gauge waters at the moment, I'm trying to find a small engine with proper valve gear and a coal-fired boiler that will suit the projected light railway I've got room for in my new garden.
I've been reading The Chronicles of Boulton's Siding by Alfred Rosling Bennet- a cornucopia of small, old engines that one Isaac Boulton bought from the big companies, renovated, and hired out to other companies, and I'm all fired up about small, old engines!
Thanks again for all your invaluable help- you've saved me a wild goose chase!
John.