Another update; I spent a few hours this weekend rebuilding one of the cylinders to better reflect the prototype. This work took much longer than I had andticipted. The thing that was bothering me about the existing cylinders was the ribbing of the main body. The new cylinder is formed from a series of disks the larger diameter one is .035" thick and the smaller disk is .060" thick". I wanted to see if I could pull this off without using a lathe, or laser cut parts. Basic fabrication techniques were used and all the drilling of the disks was done by hand with a drill in a pinvise. The thin disks were spun in hand drill with a course sanding stick, then a fine one to get the taper on the edge. All other shaping was done with flush cut sidecutters and files and a jewellers saw.

shot shows the progression of making the disks

The web extension on the thin disk

the body extension on the thick disk

right and left showing the difference on the ribs or cooling fins

and from the other end.
I reused the front plate from the orignal rebuild The difference between the cylinders is not great but I am happy with the results, now that i have worked out the method I will do the opposite one.
regards Michael