Casting kit

I saw a photo of a green twin oscillating steam engine on the Preston Services website a few years ago, and a Canadian buddy of mine challenged me to make one. Long story short, I built a foundry, used a 3D modeling program to model the engine using 3 photos, made the patterns, and cast the parts for a 60% scale engine. I recently got the engine running, and it can be viewed here: https://www.youtube.com/watch?v=UxIZ4iuhLyM The plan at this point is to finish the painting work on the engine, and publish it in Live Steam and Outdoor Railroading magazine. It was a long journey to learn the foundry work, but I was able to cast some of the parts in gray iron, with the remainder being cast in 356 aluminum.

I recently acquired a Stuart Turner 3MTB stationary engine. Unfortunately the slide valve and ancillary parts are missing. does any have or know where I could get drawing of these parts. I have contacted Stuart Turner who no longer have any of the old drawings or parts. Below is a top view of the valve chest. Any assistance would be appreciated.

Hello everyone... my name is Jason and I am from Northern Ontario. I recently purchased some steam engines from an estate sale and there is one that is rather interesting. It looks like a Stuart S50 model like right down to the nuts and bolt pattern on the valve cover.... although the crank web on mine is bell shaped where on the early Stuart S50 it is round. The people at Stuart in the UK think it is a 40's ish model based on the photos. I questioned mine because it does not have the Stuart nameplate on the top of the base... where it is located on engine. They sent me a picture of an old model without the Stuart sign on the top of the base but at the bottom instead. The people in the UK say that picture has the Stuart sign on it is photo shopped and there is really not one on it at all. On the pictures of my engine I have put a gold ring on where the Stuart sign is normally. I have never seen a knock-off anywhere online. Opinions are certainly appreciated. Stuart thinks I have the real deal.... and possibly a gem. Any thoughts on the engine? condition, authenticity, value? Thanks so much, Sincerely, Jason.