Any idea what this is?

[ploughman]

Friend of mine unearthed this from his daughter's attic.
Dejunking the rubbish gathered over the years.

Markings are CTCO S406240 and S1054B (last digit could be 3 or 8 though)

It’s heavy.

No crows foot in evidence though 

Thanks

[Tony B]

Looks like one of those things that the Royal Navy would describe as a Floggletoggle. No idea what it is what is does but it is in stores!