I am in the moment on vacation but in about 1 week or so I am going to start working on the zylinder.
I am only going to tighten the squishband to 0.8mm as the shape of the used cylinderhead is really good for high power applications.
As soon as i get home and have good internet again I will post a picture of a dude that did the same to an engine he had a 60cc cylinder but he produced 18hp of it.
The cylinder has a steel liner witch will be pressed out and the i weld or glue on material to get more space for the ports.