As of yet I've had no luck in finding a gunsmith or machinist willing to rebuild the existing striker or manufacture a replacement.
I have located a source for replacement Parker strikers at a very reasonable price. Since I currently have a Parker hammer gun I compared the two side by side. The the diameter of the Parker striker base is just a bit wider and the overall length is a little long. The length of the bases look identical. The pin itself would have to be shortened and the base diameter would have to be reduced a touch. The relieved area on the side for the set screw is much smaller on the Parker though that is only a matter of filing out some more material. If the hardened metal is too difficult to file perhaps a stone would be more effective. It seems to me that modifying a Parker striker would be a cost effective alternative to starting from scratch and be much stronger than patchwork.
John Campbell, I like your idea but the depth available for the tap hole seems very shallow.
I'm all ears if anyone here could provide any ideas or assistance.