The next bit is the smokebox wrapper. In the pre-"Weshty" days, and certainly in my sample, the wrapper was supplied partly-rolled - or rather, it was curved into a wide arc, and that's yer lot. The rest was up to the builder. To roll it even further to match the curvature of the smokebox shell is not easy, but you can use either one of two methods:
1. Get a 1/2 inch brass or steel bar / tube, put the wrapper strip under it, and roll it like a rolling pin on your thigh, or possibly even the carpet; or
2. If you have a proper rolling mill, you can form the right curves very quickly. Rolling mills, though expensive to buy, mean you can roll all sorts of smokeboxes and boilers (parallel or tapered). I bought mine years ago from GW Models, and it has been incredibly convenient. That said, the "S" smokebox wrapper was first rolled from a bare arc to a tight cylinder, matching the radius of the smokebox shell front and rear.
You then have to mark out points at which the smokebox wrapper has to be reverse-rolled to represent the vertical sides. The fixed point is at the top dead centre, where the lamp bracket has a half-etched mark on both the smokebox shell front overlay, and the wrapper itself. Using a scriber point, I more-or-less worked out that the reverse curve would have to be around the fourth or fifth rivet position from the base.
This photo shows the scriber pointing to the relevant (front) line of rivets, and you should be able to see a mark I made about four rivets above that - that's where the reverse curve will be:
I also scribed a straight line at this point from the rear of the wrapper to the front. This line MUST be parallel with the base. It needs to be done for the other side of the wrapper as well:
Self-explanatory is the whole point. Feel free to use the photos to develop your instruction sheets, or possibly put them on an explanatory photo CD for buyers of the kit.