You are being had - cheated. there will be nothing wrong with the engine only the breathing pipes as mentioned above.
The MAF will not put the engine lamp on, but the oil from the breather above will as the oil gets onto the O2 sensor, and it is this sensor that has moved from its stored settings and this puts the light on.
A new MAF if needed cost £145 from Bosch and takes all of 5 mins to put on.
OK the laser has gone down on the Sat Nav and firms on Ebay fix them for £225
The Air con may just want a charge,, go to quick fit and they will charge it up,,£40 if it works and free if it does not work
The wiring harness and new plug is quick to fit and this could be your only engine problems.
Where do you live in the UK
Thanks for replies everyone.
Thanks Television for info, just to clarify though, I have had MAF replaced & magnet and wiring harness already.The trunking to and the MAF have oil in them today, the guy that came out said it was a known problem with some of these engines breathing too hard causing the oil to be blown out of the breather on the cam cover and thru the inlet tract, intercooler and into the MAF, he said the short cure was to clean it all out but it would return or to replace the engine which seems a little drastic to me, also a google search has not revealed any engine faults like this which makes me very suspicious.
The Indie I have used is based in Weybridge, Surrey as I live and work in that area.
I have a friend who is going to regas my ac later this week and have found a company in East London who can replace the Laser in the command for £170 with a 6 month guarantee, just got to find someone to take the command out for me.
To me it just very annoying (And bl***y expensive) that this has all happened in a short period of time, its not that I have skimped on serving or anything either or drive the car hard.