I picked up this old post drill, sometimes referred to as a blacksmith's drill. It had been living in a costal town exposed to the elements for ages. It was sitting under some Tea trees, which are known for producing acid and the salt air which explain its "patina". The whole thing was completely sized nd rust welded. Not a single part moved.
The disassembly alone took me 3 weeks working on it full time.This constituted exploring CR, WD40, G15, Kero, Molasses, Electrolysis, Wire wheel, A blow torch, and a VBFH.
As you can see the casting was cracked and only that small clean corner was holding it together. I was quite shattered when it came apart. However it was successfully welded back together!
The big mother of a bolt holds the main drive gear in place and is made of cast iron. The threads were damaged and I couldn't find a matching die to see if I could clean them up. The shaft was also no longer round due to wear from the hand cranking motion. So a new one was machined up and the thread cut on the lathe.