As to the question of "roof outriggers", RS2000 supplied this on TNF:

"The Mann biography refers to welding in a "top hat" shaped cross brace to the roof in a not obvious way and that this proved the provenance of some of the cars much later on. Without ploughing through the Appendix J "freedoms" I can't recall when body strengthening became free in Gp2 but this was perfectly permissible in Gp2 in the final years but probably not then. Roll cage mountings were very limited then with none of the massive constructions used today that attach everywhere. The weakest point of a Mk1 Escort shell was by the A pillars whereas on a Mk2 it was below the C pillars. Either way, it was presumably seen as important to shell rigidity and would have been concealed by the head lining. The permitted cage then was little more than the initial hoop behind the B pillar. Later the "14 point" cage was the norm right to the end of that Appendix J - the final Escorts in the 81 WRC still had no rear diagonal, not least because the passenger seat needed to be reclined.

My main concern in later years was that we had removed the standard production roof cross brace from a Mk2 International Rally car as weight saving rather than added anything, although I'm sure it was not standard production on all Mk2 models. I don't think Mk2 RS shells had it but mundane models did, suggesting that on standard cars it was more about "NVH" or whatever the term is."