Elan Sprint Earthing Point at Rear - UK car.

[reb53]

Or, for the earthing you could simply do what I suggested 10 years ago.
As it's been fine for the last 40 years I think you could safely say it's stood the test of time.

Ralph.

[fattogatto]

I use a 4 gauge welders cable to both lower chassis bolts at the bottom of the boot from the master switch. As has been said, make sure the bolts are tight through the bobbins before tightening down thew lock nuts on top. Also use a battery terminal cover filled with dielectric grease.