Operator

Thanks for reaching out! The window operator you have here is the 39-330 RH Inverted Split Arm Operator. The link arm appears to be attached to the 39-553 Roto Sash Bracket. 

The left handed operator is the 39-329, used with the 39-554 bracket. Both operators are compatible with the 39-232 Rotot Folding Crank Handle.

Alternate image for 39-330

Side profile view with measurements

The black plastic piece in the fourth photo is the track slider for the casement hinge. This piece is not sold separately from the hinge assemblies so you'll need to replace the entire part. I'm happy to recommend a replacement for it but I'll need to know the measurement for the length of the track installed to the sill.

Please don't hesitate to reach out with any questions.