They are probably form the corporate Ford parts bin of the time. Mk I and MK II Cortinas had eyeball vents, as did the MK IV Zephyr, but I haven't had a close look at any to see if they match. Did the German Taunus have eyeball vents at that time? The vents from the later Escorts (Mk II) fit into the dash differently, but the vents from the Mk IV & MkV Cortinas have two lugs that screw into the dash as on the original GT40s. Gives you something that looks very close, if not exact.