First check out the Chevy Parts our club members have for sale at NOS and Used Parts Page
Then we recommend you try either of the following companies for Reproduction / New Old Stock / used original parts. -

Classic Chevy International           Bow Tie Chevys
PO Box 607188                         PO Box 608108
Orlando FL 32860                      Orlando FL 32860
1-800-456-1957                        1-407-880-1956

Bow Tie Chevys Home Page

Both companies publish a monthly color magazine with how to articles and sell parts and supplies. CCI is the bigger organization. A membership costs $30 per year and is a bargain if you are into Classic Chevys. Both hold national shows 3 or 4 times a year.

A special recommendation for 55-57 Chevy restorers:

CCI sells a book “How to restore your 57 Chevy” that shows you how to restore a Chevy exactly as Chevrolet built it in the fiftys. They also sell the Factory Shop manual and the factory Assembly manual. Both are very helpful to the restorer.

Source of leads to other parts you need -

Hemmings PO Box 100 RT 9W Bennington VT 05201 1-800-227-4373

Hemmings

Hemmings is the “bible” for old car hobbyists. It is a phone book sized monthly magazine with ads for old cars , parts and services to support the car hobby. You can pick one up at a local bookstore or magazine shop. I highly recommend this. Fun to read and excellent source of parts.