Have had my Multijet 2005 for well over two years and put up 40k miles.Read the threads here and shoved about a bit with a big screwdriver /file at turbo actuator bar .No obvious change .Then drowned the lot in spray oil .Man!Its like a different car .Before had ultra narrow torque band 2700-3000 and that's IT .Very little sensation of acceleration but adequate power .Felt strong on motorway .Now , get nice torque from under 2000 AND over 4000 ,car has that diesel driveability it was woefully lacking .I would imagine top speed has gone from 100 to 110 mph .The 100hp I used have ( because of low gearing ?) never would have felt as fast at very high motorway speeds .MPG not effected dramatically overall.

So did I have NO turbo or was it just not properly 'activating'?

It depends, the wastegate can clog up with carbon, so it'll not open or close properly.

With the way the wastegate actuator works, open with no/less vacuum, closing/closed with/more vacuum, it's usual for them to go the other way, clog up and fail to open properly, so owners stuff with overboost codes and trips into restricted performance (limp) due to the effort of the spring (and no vac) failing to push through the carbon to return the gate towards open as the boost peaks.

You may not suffer the above or what you described again, but chances are it'll clog up again, there are turbo cleaners out, like Innotec Turbo Cleaner which will strip the carbon out of the exhaust side, but it can be a job getting it in there.

Just a minor clarification, it is pressure that opens the wastegate on a turbo. - not vacuum.
Normally, the waste gate is closed and all exhaust gasses flow through the turbo spinning it faste and creating higher than atmospheric pressure in the inlet manifold - air is bled from the oulpur side of the air compressor of the turbo to the wastegate actuator. when a certain pressure is reached, the waste gate starts to open to bypass some air from the turbo exhaust wheel side directly into the exhaust POST turbo. this way boost is controlled. (That is the most basic system)
a stuck waste gate valve (ir is most often the poppet valve, not the actuator , will, as said above, cause either overboost sysmptoms, or often it sticks open causing lack of power. It sounds as if yours was probably stuck in a halfway postion, late boost , but no over boost. hence the lack of low down torque. Turbo seemed to be working after a fashion but came on far too late.
The EGR is a big culprit for carbon build up, best thing is to buy a blanking plate and get shut of the piece of crap.

Happy forced induction.

I looked and it seems really hard to get at all the bolts.Did I read that some of them LOOK like 'star' /Torx but are different ?

Modern (er) turbos tend to use stepped motors to close wastegates or retract vanes in VGT's, when the carbon stops their progress the motors can fail by burning out with bigger expenses, same goes for EGR operation.

Others generate the vac via a vac pump (same pump for the brake servo) as a diesel doesn't generate any intake vacuum like a petrol engine does.

Funny, my old X Type used the vac pump to operate both vanes and EGR.
It was far more reliable (and fixable) than the later models with stepped motors operating them, the fix was to replace rather then manually operate them until they freed up.
Progress eh??