Hello there!
Thanks for reaching out to us. Starting with the tilt latch, take a look at the 26-243 and 26-244 to see if the specifications match up with your old hardware. I can't be certain this is what you'll need so you will have to remove an undamaged latch to confirm.
The plastic piece is glazing. Can you remove an undamaged sample and show us a clear photo of the end profile?
If you're looking to replace the weatherstripping, you can find our selection here. You're also welcome to upload a photo of the end profile of the weatherstrip for us to review.
It looks like you may have pile weatherstripping. We would need you to remove an undamaged sample and show us a clear photo of the end profile, along with the written-out pile height and base width, to narrow down some options.
The pile is the "fuzzy" type of weatherstripping. I circled that below. Using the 58-001 as an example, the base width is 3/16" and the pile height is 5/32". See the photo below as a reference.
As for your question, the top and bottom window sashes use glazing to hold in the glass.
