Update.
First plug done, which is the 4 pin on the outer edge. Fiddly AF to get done and de-pinning the original plugs was a PITA. Not entirely happy with my crimping and had de-pin the new plug a couple of times as I got things the wrong way round.

Just not really enough room to get the pins inserted into the plugs when assembling easily.
Still, power to lights seem stable on this plug now. Just the 10 pin to do which looking at the space available is going to be even more tricky. I'll may have to remove other plugs and try and remove the wiring loom out of the belly a bit to get room to work.
Quick sanity check.... With the fuel tank removed and the dash going bonkers trying to get a reading on the fuel level, I noticed when pressing the start button, nothing happened - except for the headlight cutting out when button pressed, but no power to the starter? Is that normal? Just want to check that they may be something else now amiss. Can't tell until I get the other 10 pin done and fuel tank on.
Pete