We're practically neighbors. I'm in Port Murray, off Rt. 57. I'm available if you need technical help, Puch specialty tools or parts support.
Let that PB Blaster do it's thing for a few days and hopefully it will break free. If it doesn't, you might have to remove the head and use a large diameter wooden dowel and pound that piston out of the cylinder. Hopefully, it won't come to that.