Thanks once again for the replies.

Based on the advice suggested here, I’ve googled Smiths Mechanical Tachometer Cable guide and it took me to this page:-

http://www.classiccarama.com/classic-car-parts/search/?keyword=rev-counter-part-types

There are a number of firms offering cables of similar appearance, and I think the Beaulieu Autojumble idea is the way forward. If they aren’t identified at B, then I may contact one or other of the firms to see if they can help.

It’d be a shame to “chuck” them not knowing what they are for certain.