Chevy specific tools

[Benny the Blue]

I am quai restoring a 1950 Chevy 3100

I am finding a lot of carridge type bolts with a (I swear it looks like a little bow tie) pattern to accept a tool I can't seam to find yet.

The side bed bolts to the fenders have them, the door cranks have them, the glove compartment doors has a couple that are smaller.

So I assume there is a set of tools involved here.

Can some one dorect me to the right place o start?

Thanks