I guess it will remain a mystery :D

Thank you, I'm going to assume its on there mistakenly, maybe a carb transferred from a different vehicle?

Maybe, but isn't this the accelerator pump linkage?:

I have a Zenith 36 VI carburettor. There is a mysterious unconnected linkage arm (sorry, I don't know what it is supposed to be called) Can any one help me identify it/ suggest what it should be connected to (if anything) ? Below is a link to a photo, part in question highlighted in red, sorry...