Bob,
Section 5, Sheet 2.00 of the 1947-1954 Factory Assembly Manual identify those parts as follows:
Inner Retainer - 3683046, Spring - 3683045, Outer Retainer - 3683047, Pin Lock - 359380.
The pin lock can be obtained from Classic Parts of America (
www.classicparts.com ). They call it a "Huck Brake Anchor Pin Lock Clip 36-52, Item: 71-514, price $1.99
I don't know where you can get the other parts since I re-used mine.
Hope this helps a bit? Good luck!!
