I appreciate all the info you people have shared with me. I can't offer much in return, but with thanks, I will offer what I have found out about my SS12 917.25510. I hope it will help other "new" SS12 owners.
If like me, you take the carb apart for cleaning, and find it will not Idle after… The centre emulsion tube/jet, after installation at the factory, had a hole drilled into it, through an idle passage, to supply fuel to that passage. When you re and re that jet, those two holes will no longer lineup. No fuel for idle, no idle. Who knew? Mark the jet at the place the carb body idle drilling is. File a groove in the jet threads to allow the jet drilling to feed to the carb body drilling. Job done.
The packing "O" ring in the fuel shut off valve is a 008
I have an old Dupont paint sample binder. As near as I can tell the blue colour is a close match to, 1982 Ford "3M" paint code . And the White is really close to 1978 Ford "9F" paint code. These are my old eyes doing the comparo, please check with your own. And please share any differences.
The battery in my tractor is imposable to clamp down, it moves all over the place. I'm making a keeper that clamps between the frame and the battery tray. Hopefully this is not an indication that my engine is shot