Pella casement window shade crank - 1950s - 1970s

Located in SW Indiana. I need to know if you carry replacement shade cranks for Pella windows. It is the small crank and turner located at the bottom right of casement windows. There is a small turning knob on the inside of the window for opening and closing the blinds inside the window. I went to a local contractor who has worked on our windows for over 30 years, but he does not have those parts anymore and he just retired. The only number I have is on the bag he gave me years ago - OCJ8D050 - which may or may not be the part number. Going online I can't find anything resembling it as styles, manufacturing technique, etc. have changed. The cranks are getting very hard to turn so the blind does not respond correctly or does not turn at all. I've replaced about 7-8 in our home over the years. The crank is 2 1/4 inches long, 3/4 inches "high". Any guidance? Thank you. Mike