Right just put the cossie back together after quite sometime, it all runs fine except for smoke on idel it's ok but when you rev it you get blue smoke.
Could it be the valve stem seals as it's been sat for so long?
The Turbo is pretty much brand new only done 2000 miles before I took it off the road and it never smoked before.
Here's a video I just took bit hard to make out as I can't rev the engine and be at the back of the car at the same time

 

blue smoke is oil; it could be a few things

when you say you've put it back together, what exactly did that involve? was it a fresh build, ie. new piston & rings? rebore? or what it just old engine parts put back together?

it could well be valve stem seals (most likely) or it could be worn piston rings (if they werent new ones) or if it was a new build maybe you havent ran it in for long enough?

i put my engine back together after 11 years of being off the road, and i got a bit of blue smoke for a while even though i changed the valve stem seals - but after driving it for a few weeks it didnt do it anymore - maybe drive it around for a while off hard boost and see if it does it still

 

Rebuilt is kind of the wrong word the Head and Block never changed or the Turbo it had just been sat for a long time with lots of bits missing just got round to putting it all back together.

 

more likely to be valve stems seals, but it could be worn rings too

 

my saff did the same when i had it laid up for 4 month took it for a nice run and it cleared up