artyman wrote in post #8486444
It's a Fairlie locomotive, the Ffestioniog operate several, a new one was built in 1991 named David Lloyd George (Famous Politician - Welsh)
Actually, it's the Merddin Emrys as I mentioned in my OP.
"Itwas built in the railways own workshops at Boston Lodge and was completed in 1879. Merddin has been one of the FR's mainstays for more than a century, and has changed shape with successive rebuilds, major overhauls / rebuilds being undertaken in 1895, 1921, 1934, 1961, 1970, 1988 and 2005. The 1988 overhaul was externally sponsored and featured serious efforts to return the engine to something close to its original appearance."