Turns out that my Snap-on socket isn't an 86-F. It's a 36-F.
It's a specialty, a Cam Shaft Nut and Front Bearing Socket for old Fords.
Shows up in the 1923-28 catalog. No year mark. And the logo is like none I have seen. The big S has feet, as they say, and all the letters are in uppercase.
Big boy; it's 2 9/16" tall.
It's like the largest one in this picture.
http://s390.photobucket.com/user/snapmom/media/006-4_zps947b222e.jpg.html
