Sorry it has been so long reporting back, but the starting problem has been solved
Either utter stupidity or fuel theft
was empty, even though I had thought it was around half full @ 500ltr. Last time I looked at the fuel level tubes, it was half full, and haven't done much motoring since then
What made me twig was that the external priming pump was not picking up fuel. When switched fuel tanks
at the manifold, immediate fuel flow. Undid the front injection line to bleed air, job done.
A lot has happened healthwise since I originally posted, and that prevented me from completing the job, and posting
Anyway, thanks for all the responses, and suggestions, that's what make this forum so awesome.