Westerbeke W30/4-91 Parts (or whole engine FOR parts)?

Hello. We have a 1979 Cal 34 with Westerbeke W30. Our idle screw assembly (#19282)managed to shear the top part while we were trying to bleed the air in the fuel system this weekend. Does anyone happen to have a spare one of these lying around they would be willing to sell? Furthermore, since our diesel is getting on in age, we are looking to get another W30 for parts. If you have one laying around please let us know how much we can take it off of your hands for. Thanks! Bixler McClure