Hi Ian,
It was published in World of Model Engineering #5, one of a series of Magazines that was published a while back. I may even have the start of one of them. I was given some parts which included the start of one, but the threads were all BA which I don't have any taps and dies. The fellow who gave me the parts had completed one and installed it in a 48" Launch which I built a horizontal boiler for. When I brought the Boiler to him he gave me some parts and material as well as paying for the boiler in cash.
Gerald.