Truth window parts
Hello! This lock looks very similar to our 38-036. I think this may be what you want, but look it over and see what you think.
You also mentioned that you needed the crank operators themselves, but I can't see them clearly enough in your photos to make a recommendation. In order to make a suggestion from our inventory, I need you to remove one of the operators from the window and show me one clear picture that shows the full assembly. That way I can see everything and find you the best possible match.
I'm sorry to say that this plastic piece isn't sold separately and is not something we can provide. I don't think it's meant by the manufacturer to be replaced. The only solution we can offer is to replace the whole lock with the 38-036 entirely.
I am sorry for the inconvenience.