Casement Windows don't close properly

A quick learner from Connifer, CO says:
I have Pella Casement windows. They don't close properly without me pushing them closed. I've determined that they have the Pella roto opener (1967-1993). The openers are quite expensive, and don't seem to have any adjustments. But I'm wondering about the support arms that aren't attached to the opener. Are these replaceable and would they help the window close? I don't find a model number, but I could send a picture.
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Casey from SWISCO responded:


Many parts made by Roto are no longer available since the company has slowly been discontinuing their hardware. If you could show us a picture of your operator and the arms that move the sash in and out, we'd be happy o confirm what is still available. Thank you!

A quick learner from Connifer, CO says:
Thanks Casey,

Here's a picture of the window operator. I've identified the operator itself. There are two identical straight arms on top and bottom of the window. In the picture you can see the lower one to the right (or maybe below depending on rotation of the picture). It attaches on the window frame and on the sash. There are no adjustments that I can see for this arm.

Thanks for your help,
Thumbnail of the uploaded file named Window.jpg
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Casey from SWISCO responded:

Thanks for the photo. As you may have figured out, your windows would use our 39-175 and 39-176 Pella operators. As for the hinge, the arm looks very long in your photo but you can compare the dimensions to our 39-396 and 39-397 Pella hinge arm assemblies. If yours is larger, I would recommend contacting Pella directly for a replacement. Thank you!

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