Rear windshield lockstrip for 68 Notch

That's not a 68, then. The mylar lock strip was 1967 only. So you need to look for 1967 parts. I am pretty sure nobody makes a kit specifically for the notchback. They do make one for windshields and fastbacks. And they do sell rolls of the mylar material. Do you still have the stainless corner pieces? They can be found on eBay individually.