It has no markings, is half brass and half steel, any help identifying this greatly appreciated. Thanks

Looks like a manual winch.   Made to be bolted down, the chain is made to feed through it?

Hi,
It is not a winch. the chain is for a quick adjustment forward or reverse tighten / release, that worm drive looking thing sends a brass plate out of one end. so those teeth must grip onto the items then the brass ram is slowly hand cranked out maybe to push a sleeve or something apart. pipes maybe
That's about best I can describe its function from paying with it.

This is a floor board cramp for tongue and grooved floor boards, used in pairs.
Graeme

Thanks Graeme

Wow, it seems pretty elaborate