I have been working on this one and figure that there is really no need to make the complete pusher if you have a tube in place and even if it is half stuffed, it is possible to reface it. Here are the buttons I have now settled with, they still need a final polish and burring. They are in steel and are exact to the thou. The serr ated bit is not required. The bit inside will be tapped (to fit a current pusher part) and braised with silver. Just awaiting the pushers that I am going to cannibalize (why re-invent the wheel) to complete this one and will post finished job.
Pusher post is ready. Hole for pusher stem is tap 7 but can be re-sized. it will need to be threaded/tapped, re-faced and sized to fit. Then, it can be silver braised into pusher. The pusher will then be correctly sized, shaped (to resemble original), polished and it should be job done !!