Does anyone know where I can get one of these, I lost one some how.

 

At this late date only on EBay or a junk yard.
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Check classifies for someone parting out a S-type. I think it was also used on Lincoln LS's

 

Does it have to be an exact match? If not, search for “Tinnerman nut” or “Tinnerman clip” and you should be able to find something close. Most hardware and auto part store will have several options.

If you don’t want one mismatched, just replace them all. Your secret will be safe with us.

 

If you work on Aircraft, they are akin to DZUS fasteners.

 

This appears to be the clip your looking for??
Jaguar Clip

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