Welcome to FABO Dan, post pics when you can.
Here are a few links to windshield gaskets...
This one says they only sell 68 - 76, but I can't see why they don't include 67 Darts as well.
http://www.dantesparts.com/glassgaskets.html
Here's another from Year One,
http://www.yearone.com/serverfiles/fbshopmain2.asp?cat=1
Come to think of it, this one discludes 67 as well.. is there a difference in windshield gaskets??