Well, my ticking ended up being VICS related. The ticking must have been a loose butterfly moving around, the engine let go in fine fashion:
1 - Started misfiring, replaced plugs and leads and all was good.
2 - A few weeks later a spark plug blew out of the head, thread repaired and all was good.
3 - Driving around a couple of weeks later and the oil light comes on, the weather had been cold so I assumed with was condesation and not smoke coming from the exhaust - I was wrong. Over the next 9 days until the new engine was installed I added 7.5 litres of fresh oil and it came out black and stinking of fuel.
I've pulled down the intake manifold from the bad engine this weekend to find all the butterflies floating around (1 in 2 pieces) and 3 screws out (1 of which I couldn't find).
I'll update with some pics tomorrow...