I finally had the chance to remove the nut holding the cable stud on my standard 67 gas cap (first four pictures). As you can see, it is identical to the ones on Richard?s and John?s original pop open caps. This is a hex nut, top notched, distorted thread lock nut, with an attached, free spinning, conical washer, with red rubber sealing washer (detailed on attached copy of a page from the 1969 Ford Standard and Utility Parts Catalog). While the Standard Parts Catalog shows the 380331 nut available in both Zinc and Cadmium plated, and the MPC?s show it to be Zinc plated, mine shows evidence of being zinc dichromate plated.
The MPC?s show that this (Service Part) nut was used for both the Standard and Pop-open gas caps, and both the 1967 and 1968 Chassis Assembly Manuals, when read closely ("Same as Main View Except as shown" ; Main View shows 380331-S8).
Interestingly, if you are looking for this nut, it is shown as being used on the Rear Door Handles of 1965-68 Full Size Fords, and on the Rear Doors of 1966-68 Thunderbirds (copies of Illustrations from 1960-68 MPC attached).
Finally, in regard to the ?illusive? 52064 attaching screws for the Pop-open gas cap, I did find this screw listed in the Ford Corporate Standard Parts Book. As the Standard Parts shown in this book are engineering/ manufacturing specific as opposed to application specific, no specific finishes are shown for the detailed hardware.. All of the different finishes available at the time of printing are described in detail, which appears to suggest that any desired finish could be applied to any, or most any, of the parts detailed.
One item of specific interest to this thread, is that the 52064 part is shown to be a flat head,Phillips, self-threading screw (like those shown in the second picture of John?s Reply # 3), and not oval head, as shown in the fourth picture of Richard?s Reply # 6, furnished from his ?Down Under? friend.
I hope this gives a little more insight to this somewhat puzzling detail.
Bob
