Here's part numbers associated with the early up/down rudders. Reference these part #s when you place an order with your dealer. Note: different rudder pins for different model boats.
81390001 Early Rudder Blade
81350001 Early Rudder Mount
81360001 Early Stainless Steel Rudder Pin
81361001 Classic Nylon Rudder pin
81362001 Older Outback/Sport/Tandem nylon rudder pin
20860000 Lock Ring
8030171 Screw
8080541 Washer
Here's a link to the Kayaking P&A catalog, see page 62:
http://cdn.hobiecat.com/digital_assets/International_Kayak_2016_August_87367033_HvVATny.pdf?_ga=1.23985912.35126097.1462911695