If I recall correctly, the only outward difference between an original vacuum wiper for these two body styles and an aftermarket wiper is that one's gear cover snaps into place and held there by tension, while the other has two small screws to secure the cover. Otherwise, I think they look the same. The aftermarket vacuum wipers are reputably more robust and not as prone to body warpage as factory wipers. At least, this is what Ficke Wiper Service informed me after I had sent a couple original wipers to them for rebuilding - only to be told original Ford wiper bodies tended to swell, blocking the paddle from swinging inside. Ficke's recommended for driving purposes, use an aftermarket version.
Marshall