Wow. I just stumbled in on this thread and that's some awesome info. Sorta like everything you wanted to know about an old Weber kettle but you could never find.
Nice job!
If your kettle has a 'PATENT PENDING' on the lid vent, it should be from either 1969 or 1970. Patent (to eliminate thumbscrews for the leg sockets) was filed by Weber on 11/22/1968 and granted on 11/10/1970. Patent number should have been engraved beginning with 1971 kettles. As for the handle, Brian makes them as good as the original.