38ac,
No, just to clarify, the threaded piece has unscrewed, ( the part with the large fine thread into the head, with the square head on, together with the handwheel, ) but it will only back out as far as the end of the threads, I can pull it maybe 1/2" more against a spring, but that's it .
So I'm guessing that both halves of the combustion chamber are jammed in, with the valve stem head between them .
Looking at the parts book, the 3-1 COV is slightly different to the
5-1/6-1, so I'm not even sure that an Indian replacement COV would fit, hence I need to make sure I don't damage the original.