So continuing this on. Back home and removed the passenger seat, gone under the dash and have found the zip bag. Disconnected the door lock connector... And still no joy, fuse sc44 blows as soon as I turn ignition. It was only 15a and should be 20a (new 20a fuses turning up tomorrow) so not completely lost yet but not promising. Fyi the 15a lets me open the boot so again pointing me to the passenger door as area of fault.
I've seen some folk have removed door card with closed door but am hoping to avoid this as would require base to be removed along with the leisure battery and everything else down there.