left and right hand casements
Thanks for posting. This looks like the 39-187 operator (its opposite-handed version is the 39-188). However the link arm on this operator is 5"; what you show is closer to 4". Unfortunately we don't have a version of this operator with a 4" in arm. You have a few options. First, you could try installing the operator as is and see if is compatible with your window. If it indeed does not work, you could then try re-positioning the sash bracket to see if that improves the operator's function. As a last resort, consider drilling out the link arm on the new operator and attaching the old one to it with a 62-014 rivet. Let us know if you have any other questions.
I am sure I am not handy enough to do all you say. Is there somewhere else I can try that may make the right size?
Not that I am aware of, no. I'm sorry for the inconvenience. I don't think you'll be able to repair these windows without a fair bit of handy work, so you may want to consider contacting a local professional to do it for you.