Email it to the head office of Lee Valley Tools. Those people really get off on old tools.
Apparently, the Lee boys have even more old tools than Dad Leonard Lee had.
That's bits of what you see on catalog covers.
Looks like some sort of incomplete kit. Like there would be a couple of things in those rings, maybe things that get hammered in. The hammer appears held on with a finger tightened screw, not the usual thing for a permanent fixing to spin around. I would expect that the handle would be held down between the rings somehow, tied perhaps. Pick the whole lot up, carry, plant main spike, remove hammer and other items, use, re-attach and relocate.
People often bodge kit for their own needs, a one off for them that others might find other solutions for. It might not be possible to find out what the need was unless you find the bodger to ask them. Not helpful but at work they're past masters at bodging. Victorian spirit I guess.
You've got me intrigued so I hope you find the answer and post it here. I don't like cliffhangers that don't get concluded!!
So you remove the hammer to actually use it?
Seems extreme to tie up a specific hammer for that one task. Why would a person do that?
Is it a special hammer or a job that needs doing often, something like that?