Okay, this is my step-by-step set of instructions for the conversion of a RailRoad Flying Scotsman into the proposed Peppercorn 4-8-2, based in part from Mr King's own builds. In terms of experience rating, I would rate this as a 3/4 star in terms of difficulty, if only because of how I jump around from picture to picture. Prior experience of kitbashing locomotives is required, as is the assumption that you know how to alter Hornby wheelsets to suit your needs. My original notes have been misplaced, so I'm making this up as I go from the pictures.
1. The starting point - not for the faint of heart - set up the two chassis blocks in a vice with the axleways alongside but staggered. Cut carefully through the metal with a junior hacksaw, and tidy up the faces.
3. The body - suitable cuts made with a razor saw will deprive the footplate of most of the boiler and smokebox. I used the existing smokebox in another build, but yours could be reused with suitable thinning of the plastic. The footplate was extended using plasticard strip, and test-fitted to the chassis for length.
6. New smokebox. Mine was made using a leftover part of the original boiler (turned upside-down and the top filled with balsa before sculpting). This was then stuck to a balsa plug sat in the open-end of the boiler.
7. The distinctive deflectors were made as a single piece, wrapped over the smokebox and plug. I was fortunate that the boiler paper matched the plasticard in thickness. They do not need to be fitted all of the way around the boiler plug as access holes are required in the original design. A box of plasticard was also added to the front-end to simulate the third-cylinder location.
9. The tender was not left alone. The coal load was carved out, whilst the rear plate was removed to be angled slightly. The plastic behaved well with gluing, and topsheets could be added minutes after the rear plate was relocated.
10. Holes were cut into the topsheets to provide access to the tender filler and coal spaces. A mixture of disc-cutter, small craft-knife and emery boards were used to open out the spaces. A further sheet was put inside the tender coal space to hide the former tender-drive mechanism.