Hex Head with working man image

The D-15 is down to mostly frame and suspension.

Took off some small bolts and they have a design on the head: a large 'F' (sort of) with the image of a standing working man with one arm straight out and one arm reaching up to a top shelf (the top line of the 'F'). Also has the little r in circle registered trademark. Pretty intricate design for a small 7/16 bolt head. Anyone know the story behind this? The underside of the head has a thin washer lip and the .nut has a checkered surface. Never seen anything like it.

It came off the the two piece housing that goes on both sides of the frame where the emergency brake cable goes through.

Didn't think a photo that small would turn out very good but I might try anyway.

Thanks.

yes a photo would be useful.

Here's the photo

that is great. thanks. i had not seen one of those before.

Where could a person post this picture to find out more about it?

I looked on Internet, did searches and searched images as well using a bunch of different search phrases. Nothing came up.

I'm just real curious because it's a real detailed logo for the top of a small bolt and has the (R) in circle copyright too...

Possibly the image is not a F as in ford...something else is being represented. I have never seen one but now starts the search..