Look at the 12 valve section. there is a ''sticky '' on the top of page yhat explains how to , why to , and who has 'em. What you do is use the jig and send it to the next person on the list. Nice idea to be courteous and tell the keeper of the jig [ by PM'ig him ] when you are done and also PM the next guy on the list that it is coming. Please replace any parts that you use.
For more info, ,hit search bar and type in kdp and jig. Enjoy.