The drivers door locks by pushing the handle forward or back. The passenger side locks with a key. But you knew that I would find the dimensions of the original handle and call these guys:

http://www.carolinacustom.com/pages/main_pages/online_store_page/online_store_page.jsp

They had parts to get my plymouth pick up doors working.

56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d