[happy1]

Thanks guys,
In my case it's a JCB 444 engine (for tractor / machinery), not an Isuzu...
Since you think 800 grit (wet with WD40) is rather course, (it didn't look that way to me) but I will switch to a quick gentle round of 1500 grit when finishing it off. I used a long stripe of paper and had in a U-shape over the journal, and did a few light movements backwards-forwards, so I don't recon I have 'done' anything measurable change to the journals.

Yes I know I'm taking quite a chance on that injector pump, but the filter just before it still had only clean diesel in it, and the pumps look like it has diesel in it, so I may be lucky. If not I can find a s/hand one off ebay for about $1k.
Timing the pump is a pain, as I couldn't get the engine to TDC before disassembly, but I made some marks on the timing gears and locked the pump at that, so will assemble it there, and see if it runs.

Cheers,