Thanks to Aadje and everyone else who has complimented my work!
This project nears completion and I was hoping to bench test over the weekend. However, a couple of small probs have arisen.
The male threaded bit of the expansion valve snapped as I was screwing it in to the manifold. It's a standard part and I have ordered a new one which will arrive on Monday.
Also, as I was tightening up the pipe union to the steam connection of the pressure gauge, the back of the nut was pulled right off. I've never seen that before! The back of the nut was really thin (like a washer) and it wasn't even tight when it gave in.
The jury's out at the moment on whether to just replace the whole pipe or get lsjms round here with his Rothenberger and remove the nipple, replace the nut and braze the nipple back on.
This is the 4th part that has snapped under the spanner on this machine. I like to think I'm not a heavy-handed worker. Brittle brass
Meanwhile, here's some more pics...