Thanks for all of the suggestions, help and personal messages offering assistance.
I have got the cases back together. I heated the right side in the kitchen oven when the wife was out and it slipped right on without even using a rubber hammer. I have now started to assemble the ignition/flywheel, the gearshift etc.... I just need to get a few new things a seal, a lock nut for the kickstart spring holding nut ( is that avaliable?), the four long studs to hold the cylinder and head, a new set of rings (which i have to figure out what size they are), a holding washer for the sprocket, so really not all that bad considering it came to me as a basket of parts that changed hands a few times before I got it.
I was looking at the manuls and saw that there is a speciality tool for clutch spring installation and I thought that I could make something simular.... but as I worked my way through the boxes of bits I found this modified power driver bit from the previous owner so I decided to make an improved one using an old nutdriver.
Sunny