The problem stemming from the shared folder structure being owned by root, not pi.
I've come up against the following headfuck...
This terminal command successfully mounts the shield folder, but as user pi, i have no write access ( and various combinations of sudo chmod 777 etc didn't seem to make a difference)
The following is an edit to the /etc/fstab file that I found online, which successfully gives me write access to the nvidia folder, but not everything that is in that folder is visible... loads of files/sub-folders don't appear...sudo mount.cifs //192.168.0.23/MediaVolume/NVIDIA_SHIELD/MEDIA /home/pi/Shared/ -o user=mediashare,password=******,vers=1.0
//192.168.0.23/MediaVolume/NVIDIA_SHIELD /home/pi/Shared cifs username=mediashare,password=******,workgroup=WORKGROUP,file_mode=0777,dir_mode=0777,uid=pi,gid=pi,forceuid,forcegid 0 0
It's driving me bonkers... has anyone got any solutions i'm missing in my linux ignorance?