Repair parts

A home owner from USA says:
Hello I'm trying to replace tandem locks for five casement windows in my house. I tried using the repair parts link but it didn't work. So my problem is that there are three different sizes of windows and different distances between the locks. The lock part numbers are all consistent, 135143. Two window locks (with the silver track in between the locks) measure at 39 15/16" (40"); another one at 29 1/2", and two windows at 41 7/16" (41 1/2"). They were measured from the top of the top lock to the bottom of the bottom lock. What part should I be using for a replacement? Pictures included.
User submitted image of their window hardware.
Profile picture of Paul
Paul from SWISCO responded:
Your photo is showing a SWISCO 38-146 lock, which fits windows 40-13/16" high or less, so our part should work for your shorter windows. Let me know if you have more questions.
A quick learner from Connecticut says:
The problem isn't the actual locking mechanism. The locking mechanisms are all the same. It's the gray bar/track in between the tandem locks that differ in length. How do I find the correct part when I only saw two lengths listed on your site?
Profile picture of Dave Sr.
Dave Sr. from SWISCO responded:
I think I see what you're saying. You need a multi-point type lock. We have the 38-148, which is 29-1/2", and the 38-149, which is 40" long. Take a look at both and see which one would work.
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