Two questions:
Got a part number?
What's the applications the two types?
Jim
Of the round flange one, specifically no. Could be something from Ford or might not be. The not round flange part was super common on countless Fords for years. They are available used, new old stock, and as reproductions. Sellers of NOS and NORS Ford parts often describe the not round part as 358817-S8B. I have a few NOS ones.
Research is a work in progress but the round ones have been found as Cobra parts 1962-64 in new car pictures and in truly unrestored Cobras. I also see them included with Ford 2100/4100 carburetors for sale on eBay(R) from time to time, the last on a 1964 model year 4100 series carburetor. One was offered by itself in an eBay listing a few weeks ago but it was corroded badly. Finding them on used Ford carburetors for sale is encouraging that it could have been a Ford part if only a service part.
Shelby American, Inc. obtained much but not all of the small hardware parts to install engines and transmissions in new Cobra chassis from Ford Motor Company. In comparing various Ford sourced parts it seems Shelby's works got some hardware from whoever supplied Ford on the west coast because it would be in some way different than what was being used in the east. Shelby's works bought some hardware through Dorman Products and other suppliers local to them. In late 1962 and early 1963 Shelby American bought 1962 Corvette radiators, expansion tanks, and GM(R) marked service hose coolant hose clamps to use in new Cobras street and race. Who supplied the round flange wing nuts? Was it a west coast manufacturer version for somebody? I would like to know but in the mean time I sure would like to find at least two in good to excellent condition.
Dan