I can't tell you a great deal about this one yet, I only bought it yesterday and I'm busy ploughing my way through the three huge ring-binders of documents that came with it (which start with the 1926 buff logbook and end with last year's 10 year hydraulic test).
Built by Aveling & Porter of Rochester (as all the best rollers were!) in 1926, it was bought by Northamptonshire County Council and worked at Brackley.
It had several private owners subsequently, before undergoing a heavy overhaul at the Severn Valley Railway in the early 1990s. There is a strong family resemblance to my 8 ton C-type, which is a single cylinder machine - both are piston valved.