After cleaning up all the destruction in the arm, check the clearance with the pivot installed. If there is play, replace or since you are a machinist make a sleeve for better fit?
The debates still rage from people who still want to use rubber. That's terrific if you want the same miserable handling from 1970. This part is for people who understand the difference and are seeking a higher level of performance. Delrin is a popular material for suspension bushings due to its stiffness and durability. They offer precise movement and will not "walk" if the torsion bars are pushed forward all the way.