Any good professional-level parts store such as NAPA should have the part listed. Forget about dealing with the mouth-breather computer jockeys at places like Auto Zone for parts like that. Even some of the online parts places might have it listed if you provide the right information during a search. It might be necessary to fabricate your own operating rod from a piece of heavy wire like a welding rod. It's pretty unlikely a dealer would have a parts list going back that far, and even if you had a part number, it probably wouldn't be available. It's not difficult to make a rod, however.
Jerry