By popular request here's an update on my Simplex project.
I've been slowly plodding away at it mainly reworking parts to my own satisfaction though over the last month I haven't had much shop time due to family commitments holidays and get togethers etc.
I've been concentrating on getting the smoke box up to scratch, the one supplies was fabricated from steel this is OK in itself but, this one had been lashed together and it would be far from vacuum proof which is a critical requirement for a smoke box if it is to function correct and give a good draft to the grate. So I decided to salvage what I could from the old one and make new where I couldn't the front ring was a GM casting so that could be reused, and I ordered a new smoke box tube from Blackgates and I drop luck with the rear ring as I had a slice of brass that was just the right size.

Machine it up using my big four jaw for a tight fit on the boiler

This is what I had to show for my efforts
A rear ring

And a pile of swarfe

The front and back ring were silver soldered into the tube, and the assembly set up on the spin indexer and the hole for the chimney bored in.

Index 180 and drill the holes for the blast pipe and the steam inlet

I then made and soldered into the smoke box the adaptor for the chimney (no pics)
The chimney sadle itself needed tidying up as it was left as cast so it fitted where it touched, this required the sadle being skimmed up with a fly cutter set at the same diameter as the smoke box tube.

Next up were the blast pipe and the inlet connections these were just made as T connections as I'm a bit of a smooth flow type of guy I wanted to make the pipes with a gradual bend.
So I got some pipe with a bend that was about right from the scrap yard, and some elbows from B and Q and cut them to make Y connection along with some screwed bushes.


And silver soldered them together, this is what they look like fitted in place

And here's what things are looking like the moment wit the boiler set up.

I had the boiler pressure tested to 1 1/2 times working pressure just to make sure everything is OK before I go and spend to much time on plumbing it in, I'm please to sy everything was Ok which it should be as it came with a boiler certificate.
I've still got more work to do on the smoke box it needs drilling to match its saddle and the sinfter valve and blower needs plumbing as will as the wet header.
I'll slowly work from front to back plumbing things in as I go
Stew