Sash lock
I'd be happy to suggest a lock for you, but in order to do so I will need a clear picture of the front. Your current picture only shows the back.
Please let me know if that would be possible and we can work from there.
Thank you. That lock appears to be a match for our 38-144, which you have already purchased from us. Looking at your photos, the plastic mechanism itself is a different color, but I otherwise don't see any major differences in design. The keeper also appears to be identical to the style used with this lock, which is the 38-276.
At this stage I'm not sure why the 38-144 didn't work for you. Based on everything you've shown me, it should have. Can you go into more detail as to exactly why it failed?