Good question. Early-build BJ-7's (May 1962), such as mine, have three-piece quarter / vent window seals and opposed to the later one-piece. While the originals are still fitted to the car and are in OK shape, I've been looking for a three-piece replacement seal for years. Also I'm not sufficiently motivated to have the originals molded and cast in modern rubber which I know can be done with good success.