success in welding the clutch slave cylinder and gearbox sprocket cover is to remove the sleeve fitted to all models (except Anni 1200), which reduces the bore size from 35mm to 30mm or 31mm depending on what you have it fitted to. the next and obvious thing is to cut out and prepare anything that needs welding yourself, I never was any good at welding cast alloy, so I use a mate, he always appreciates the "vee-ing out" bit, but when done, utter cleanliness is also vital, so clean with a de-greaser, and then brake cleaner, and then put it through the wifes (if you have one) dishwasher, but take out the salt, I did at one time keep a secondhand dishwasher ready and plumbed in near the workshop for this purpose, but the damn thing packed up and I cant justify getting another.alternatively boil it in a big pot of water, and do it a couple of times. Even then the casting quality is very often not that good, and an air hole, in it close to the weld, can (an very often does) expand and blow a small lump out of what you are trying to fill, very frustrating, but hugely worth the attempt. Once done, you may have a fair bit of artwork to do with your Dremmel, to get it looking right, and re-polishing, then there is the sleeve to refit, into what is inevitably a damaged bore and will need the use of a Bridgport to get it back, and don't forget to drill and tap the hydraulic connection and fit an extended hose union, that does actually screw into the bore (ie sleeve) of the cylinder, as opposed to just the casting, with a "lead in" hole to the sleeve, thereby preventing future aggro.
CLEM