A quick learner from New Mexico says:
Hello - I am looking for operators like 39-139 but need rear-mount. I saw a comment that suggested part #33-205 but I am unable to find that in your catalog. Am I just missing it, is it still available, am I looking for the right part number??? Thanks in advance for your help.
Thumbnail of the uploaded file named living room window operator.jpg
Profile picture of Bob
Bob from SWISCO responded:

Thanks for writing in. So what we've recommended in the past is to use the 33-205 threaded nut to reverse install the installation screws on the 39-138 and 39-139. We've installed these with the help of a bench vise; you just press them into the holes at the front of the operator base. Let me know what you think. 

Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 4-7 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at 856-317-6263 or at help@swisco.com.