How to tune a Rover SD1's V8 engine reasonably well enough given imperfect circumstances

With the battery charging light still on when the car starts, my thoughts turned to a low engine speed. I'd tuned the V8 in the summer after fixing the the FASD plus other minor work (e.g. fuel filter, timing, cleaning vacuum ports and so on) and it was fine, if ticking over a little on the slow side. Unfortunately, I didn't really make much of a difference but if you're interested in how such a car is tuned, here's a video. Oh - and without giving away the ending, I have made some really good progress since but if you have any tips, they would still be welcome! Edit: uploaded a second time to correct the orientation of one of the segments