Collecting - Cable

I received a very kind gift recently of an oak box with a slice of cable inlaid into it the lid.  The underside of the lid is stamped with "British Insulated Cables Ltd Prescot Lancs".  A quick bit of research has found that they changed there name to the above in 1925 and changed their name again in 1945 to British Insulated Callenders Cables or BICC, after their merger with Callenders Cable and Construction Co. This at lease narrows its production down to a twenty year window.

As for identifying the cable itself this has proved a lot more difficult. Its clearly a lead sheathed power cable but beyond that I am struggling .

I think the next step will be to find a catalogue from BIC during that era which will hopefully have a description / drawing that matches.  Failing that the Liverpool Museum seem to of inherited much of the companies archive so that might be an option.  If anybody has any ideas I would love to hear them.