The part numbers RonM posted are for the "completed assembly" (including the trim, carpet, handle, etc...), that Fisher body used. The part numbers Phil posted are for the bare door panels. You won't be able to get the completed assembly anymore (and I really doubt you'll find the bare panels anymore), but Phil's part numbers are what you should be looking for. As of 1971, they were still available for $58.10 each. Sometime between 1971 and 1976, the passengers side was discontinued, but the drivers side was still available at a price of $89.25. Then sometime between 1976 and 1980, the drivers side was discontinued.
Ed