Well, it would appear it wasn't the ignition switch after all! That was definitely the fix before (when I started this thread in June 2013), and with all the same symptoms this time I figured it a no-brainer. My only focus being on changing it over.
Anyway, I swapped it today and cleaned the gearbox earth strap points for good measure (which were pretty rough and had some moisture under them and in the bolt threads) and the van started with barely a flick of the key! While the toolkit was out I thought I'd quickly swap some knackered exhaust gaskets that were causing a noise and when I went to fire up to hear the fruits of my labour: NOTHING
So, work cancelled tomorrow and I'll have a prod at the starter motor, as all fingers point there.
Keep you posted!
