UPDATE: Thanks once again for all your help and suggestions, but after nearly getting stranded in Ravensthorpe WA, we eventually limped into Albany and a mechanic was able to diagnose codes off it and found that 2 out of the 4 glow plugs were not functioning and this was causing ridiculously hard starting. So, after 4 new glow plugs and $700 lighter, she starts first time everytime and the dash lights are doing as they are meant to be doing. Fingers crossed from now on!