The steamchest cover on top needed finishing off with steam inlet and blastpipe. The smokebox was temporarily slid back into place and the blastpipe position marked through, the resulting position actually necessitating a pad be silver soldered in place to act as a decent seat. This was subsequently machined, drilled and tapped at 6 deg to the cover itself, so the blastpipe points vertically once in position on the loco. The blastpipe top was threaded ready for some trial and error to find the best nozzle size later. Once that was done, it could all be connected up and tried on air. In fact, the photo above shows the valve in motion, so it did work. (Phew!). Here's another view, to record the fact the wheels are going round. As can be seen, the knuckle joint is just temporarily held in place with a brass rivet to make it easier to fiddle around with the valve timing, but it does run so with luck it shouldn't be too hard to find a reasonable setting. Straight out of the box, it runs better in reverse; once a decent compromise has been found, it can be taken down again, and the cylinder assembly completed with gaskets or sealant etc.