Regarding changing the newer center pin/extractor rod for the correct old style with "mushroom cap" I looked them up in Numrich and found two styles.

Extractor Rod, 2-11/16", Stripped, Used (2 Piece Style) (requiring the addition of the mushroom cap, I believe)

and

Extractor Rod, .45 Cal., Early One Piece Style, Used, Blue

which one should I go for?