This is one of the easier parts to find that I needed for my '69 Charger. You have a choice of oem/nos Chrysler or aftermarket replacement and a wide variety of prices.

Chrysler part# is 2889565.

ebay has both;

http://www.ebay.com/sch/i.html?_odkw=288...ay&_sacat=0

Aftermarket sources;

http://www.summitracing.com/int/parts/cwa-2889565/overview/

http://www.autopartswarehouse.com/sku/Crown/Relay/2889565.html?redirect=1

It is the same for many models and years, A,B,C,E bodies etc so if you know of anyone with parts cars, that is a possible source also.