...or you could mail me on carsupport@xs4all.nl for a pair of Mk 1 in-line grounding leads.

Although there are only a few of these left, I will be able to get them re-manufactured pretty soon. They do have an eyelet for grounding, but this could turn out to be a good way to attach it to both earthpoint and the sled metalwork. I have this setup built into my sled harness.