Charlie,
Search the wrecking yards. Some of the old half tons had a dash mounted hand lever park brake. (horizontally operated) Same style was used on Corvairs and other budget GM's in the 60's You can also check the bigger 2.5 - 5 ton trucks for a dash mount hand lever. (vertically operated) My 78 GMC 6000 has one. Not a really popular item, so they go pretty cheap.
Jeff
