Almost two years since I started this! Anyway its getting tantalisingly close now. So thanks for the help and advice.
One name to add the credits above the usual suspects is Charles Ping for letting me know what a Meyer expansion valve was - didn't know when I started this. To be honest, I haven't made the valve yet, it just runs on a standard simple slide valve. And apologies to the guy who pointed out that the style of lubricator I was making was a "Shapely Lady" - I've lost your name.