Thanks for the reply! How do I find out exactly what replacement stem i need please! I’ve just had at that pdf file you’re just sent & i can’t make head no tails of the item required mate! Sorry to be a pain! 

Game on! ST36 has arrived, but there's still a few questions and I'd be grateful for your help. I've got a set of cheapo Chinese screwdrivers that I bought years ago, so I'll use it for now for learning. Decent tweezers in the post. I also have a clip-on cheapo Chinese loupe 5x. Looking at the ST36, I am guessing that I need a 10x? I happen to have a (cheapo) digital microscope too - am I better off just learning to work under the microscope right from the start? For oiling, am I really better off getting automatic oilers, or should I learn with regular ones? Any of you folks use geiger counters? Are cheap ones (~£20-30 off ebay) good enough for checking watches, just in case they are hot? I intend to avoid lume unless it's tritium, but you never know what you're dealing with.

If you're confident you've got the correct stem then here's the movement details. Note that it involves removal of the date wheel to access the keyless works.   C01.211 Technical Manual.pdf

Sorry for the slow response. I don’t think this is a variation of the tool I posted. It looks like a 3 spindle centring tool, which is a more complicated version of what is often called an uprighting tool or centring tool, as seen here :  Best Regards, Mark

I ordered a tap 1.00 stem for the moment C01.211 & a new Tissot gold crown for the watch! I’ve tried putting it back in pressing in the detent button, but it feels a bit springy when I try to put a bit of pressure on it? Do you know where I can get a parts list & a brake down of the keyless watch parts details!