This vintage tie clip set was on eBay. It sold for $32 yesterday (Plus $4.90 shipping).
“Offered is a Vintage Willys Overland Jeep 3 Pc Cufflink & Tie Clip Set … This set is NOS and was part of a lifelong Willys Overland Jeep executive’s estate. It is marked/made by Mercury Industries on the back of the tie clip”
To help date these, I bought mine from an aftermarket Jeep parts store in Stockton CA in 1975. Still have it.