Well after calling round and driving round for nearly 4 hours this morning, I got just south of nowhere.
The bolt supply place could not sell me banjo bolts of any description, the hydraulic supply have nothing available smaller than 10mm, nor would they order it.
The diesel injector specialist wanted to drill out all 4 injectors and retap a larger metric thread into them for about $200. Oh and the engine rebuilders said no.
So I thought I would be a bit cheap and ruff with the job, by slicing a cut length ways down a bolt through the threads to make it into a kind of banjo. Trip back to the bolt supply place with injector in hand, and they could not match the thread. So still nothing.
Open to suggestions.
Also I realised that along with the banjo bolts in the same box no less I have put the nuts which hold the injectors into the head, would anyone know the size of those nuts, looks like its back to ordering online.