Pusher Replacement for the BCE

[beanyboy]

I bought a great BCE from King about a month ago and have enjoyed the heck out of it. However, I lost one of the pushers and it's sheath, although I still have the stem. See picture below. King was kind enough to send me another pusher, sheath and stem, but the stem screw is too big. (Meaning: the replacement pusher boring is too small). Is it easy to replace the old stem with the new one? Or should I just take some suggestions on who best to send the damn thing to for repair?

I will leave it to the experts and await your kind and thoughtful suggestions...

Beany