Tacho loop wire

Bit of a long shot, but does anyone have the little block and loop wire off the back of an Escort or Capri tacho?
like this one

 
I think my tacho is out of a Capri and it didn't come with the wire or block on the back.


 

The wire is just a simple double loop with no actual connection. Its the little nylon block with the metal top and sides that is the tricky bit. See the two metal bits either side of the threaded post on the tacho? Well the little metal piece goes over the nylon block and down each side touching those  metal bits forming a connected loop that allows the tacho to read the signal from the coil and work out the revs. It shouldnt be too hard to make that bit up, but there is more going on than meets the eye.
Here is some essential reading.     www.spriteparts.com.au      Look up tech tips and then on the side bar under tachometer.    Cheers,...ron.

Hi Pete
Pretty sure the old smiths tachos have the same block (MG leyland Hillman ETC).