Sliding lock
Thanks for you post! The casement lock you are searching for reminds me of either the 38-138 or 38-139 Roto Multi-Point Lock. To determine which of these is the right fit for your repairs, you'll need to carefully look over each of their dimensions and compare them.
The measurement for the distance between the installation holes is the same for both locks.
I believe the part you are searching for is the tie bar. I'm afraid we would not be able to provide you with a replacement for it, unfortunately.
Our tie bars are not interchangeable with the one you have.
I apologize that we could not be of more help with this part of your repair but please don't hesitate to reach out with any other questions you might have.