Dumped the rivet for a machine screw countersunk m6 which did not fill the hole at top of the cylinder so I put a small sleeve inside there, used a nylon locking nut and lock tight other side. I trimmed a HW95 slip washer which I'll replace with a homemade top hat in the future. HW95 spring works took a little too much off a number 8 but shoots fine just ordering a No. 7 to drop in and it'll work much better.