Jeff : Thanks once again for posting some pictures. It's good to have some more 1968 info.
A word of caution though for those viewing these. The bezels and lenses shown with the Dash Panel appear to both be the Scott Drake reproductions. I say this based on two observations. First, the use of "SEAT" for the Seat Belt Warning Light only has been shown to appear on the reproductions. In the research and documentation done so far on 1967 and 1968 Mustangs with the Safety Convenience Option, the majority have "BELTS", and two have been noted as "BELT", singular. And secondly, the steel "tubes" to which the bezels/ lenses shown in your pictures are attached (the reproduction bezels/ lenses do not come with these "tubes") are not correct for the Mustangs or the non-padded console Cougars. The correct tubes have the "prongs" that hold the assembly in the dash panel or console, located right next to the "mushroomed" end of the tube (see first picture attached). The "tubes" shown that are attached to the bezels clearly show that the "prongs" are not at the end of the tube. These tubes were used on the Early Cougars with the padded consoles and on most 1964-67 Thunderbirds (see second picture attached). These "tubes" can only be used successfully on the Mustangs with the addition of a 3/16" spacer.
Thanks again,
Bob