Problem sorted !!!
My engine now runs smooth and screams its way to full revs, and boy is this thing AWESOME.
Im not too sure of the exact problem, but I did find a few interesting things.
The MAF on the air box, when wiggled, changed the engine note, on inspection the power connector blades were over strecthed, causing an intermitent connection, pushed them back together to ensure good connection.
Also on the MAF the insulation had worn out where it passes through the rear bulkhead, My grommits are not 100% completed.
The ECU hadn't gone through its "learning" phase.
In order to do this (Acoording to ElsaWin) the ignition must be on, but the engine not running, leave it for 5 minutes. For the ECU to do its tests.
Then when started the coolant temp must reach 80C.
So i left it idling for 5/10 minutes until my rad fan kicked in when set to 80C.
Then the revs much reach 3500rpm.
Applied the throttle, and now the mid range misfire, didnt happen.
Slowly increased the revs and "WAAAAAAAAAAAAAAAHHHHHH"
the engine is screaming.
Blipping the throttle down to full revs, the engine picks up instantly, and runs down when accelerator is lifted. With a few nice exhaust pops and gurgles as the engine revs decrease.
Got told off by the wife though, as the exhaust note caused everything in the house to shake. Dont piss off the neighbours!!! I do live in a quiet cul-de-sac so I could see her point.
I also set about bringing up some more electrical circuits, indicators and hazards are all working, side lights work, switch backlighing, and washer pump works (no fluid, i dont have a windscreen yet). Woohooo!!!