1967 Barracua Windshield Gasket Identification

The picture you have of the rear gasket has the locking strip which you mentioned, this was only used on 1967 Barracuda's. The 67 model didn't come with stainless trim on the front or rear, only 68 and 69, this is probably the reason no clips are present. Not saying one couldn't add the trim from a 68 to 67, you would just need to inquire with someone that has already done this procedure to know what's involved.