Fitted the same to mine late last year - pretty easy to follow the instructions provided.
I did manage to find the grommet back through the firewall on the drivers side - its just under the master cylinder and had to bend the heatshield back/pull insulation back a bit.
i have a 67 EU6 ...i must admit, i didn't look too hard and certainly didn't look behind heat shields etc as by then i'd already pretty much decided i was going to go off piste and freestyle the installation a bit