So After my fight with the catalytic convertor, I ended up drilling out the left over studs. I'll now use nuts and bolts when it comes to replacing them, mainly because its simplier and in the future if it becomes a problem I can but them off.
I noticed the gasket between the turbo and manifold had blown so that was replaced... the blow torch has been getting some good use recently to say the least!
Once that was completed the painted manifold was replaced and the turbo unit put back on lining up the oil feed / return pipe.
I chose not to paint the turbo, Ill be getting a turbo blanket to keep the heat in on the exhaust side, hotter air flows faster so it should leave through the exhaust quicker and help spool times, this will also stop heat soak into the engine bay and keep everything running a little cooler, not much but every bit helps!
As well as this the water housing was connected and its already beginning to look a mess again. I will be replacing most of the pipes with new, but ill replace the pipes one by one once its rebuilt and that should clean it up further and also at that point do away with pipes I dont need like the relevant vacuum ones.