38 ES 2 Piston ?

Yes. You will need to trim the skirt to miss the flywheels. I set it up on an angle plate on the lathe cross slide and made a tool to mount on the face plate to fly cut the radius on the under side of the piston. 

How do safely mount a piston? The only solid bit surrounds the pin.

I used a length of bar the same diameter as the small end, cross drilled at each end as close to the piston as possible. The piston s flat topped so it would clamp directly against this. I found a length of ground bar in my odds and ends so this was perfect.