I did a google search. Try snipped-for-privacy@vintagejag.com. He runs Vintage Jag Works in Idaho (I think) and has a whole raft of fixes for different jags.
H> Hi
> I need to know how to go about wiring a Jag tach -
> it has earth wires connected to the casing, but
> what are the two connectors on the right hand side (seen from the rear) for?
> There is a round connector (upper) and a flat connector (lower) that dont seem
to be wired
properly, since my tach doesnt do anything.
>
> Regards,
> Paul