Glad you got it sorted OK Danny.

Feel for Rob having gone through all the frustration and hair pulling not to get a result
On the positive side there were alot of good pointers through Rob's original post which for me, participating in FOG, is what it's all about.
Remember a small independant garage owner telling me it's all about basics.
DIESEL - Compression and fuel and it will go
PETROL - Compression, fuel and spark and it will go.
Not so simply when your pulling your hair out - so I'm going to go on and ask is there a simple way of measuring the spark strength going to individual cylinder (without paying for a full diagnostics test)?
Compression tester for compression - easier on a petrol.
Fuel - I guess by cracking fuel lines in staged points (not undoing fully)