Thanx everyone who replied, especially Madeinjapan who got my focus onto possible fuel-flow issues!

I have fixed the "No start" problem by replacing the fuel filter, I did a few other things to help stop the "reluctant to start" issues I still had as well and now my 850 starts first time and runs better than ever!

New Items.

Fuel Filter (No obvious reasons but looked like it had NEVER been replaced (212K miles)
Distribibutor Cap (Old and Pitted)
Crank Position Sensor. (was not the culprit, but didn't do any harm to replace)
Alternator (bearings dry and not charging new Battery efficiently) This item was a Biatch to replace)
Haynes Manual (never would have found the hidden bolts on Steering pump without it)

Other things I did.

Checked Vacuum system and repaired a break on Hot/Cold intake flap valve (I broke it during attempts to repair car doh!)

Checked all contacts and wiring to sensors)

Cleaned Spark Plugs (were in good condition)

Added Redex to Petrol Tank as I believed the intermittent "reluctant to start" problem was due to low compression (sticky valves)

Added Oil Enhancer to also help with valves and YES these two things fixed the problems I had since owning the car :¬)

Now All I have to do is replace that damned rear-main-seal, yeah right, I'm leaving this until Springtime.

Cheers

David