Scout 1.8tsi Revving Issues

I have owned this car for five years and taken it from 70k-125k and have loved it for it's smoothness, decent power and reasonable economy. I bought the car fully aware of the  scraper ring issue on these engines and chose this car as it has a receipt for £8200 from Skoda for a new short engine @ 68k due to said ring issues.

Since buying it I have maintained it myself with a service every 6k to keep it sweet. It has always driven well and gave no issues. Very occasionally (at most once a year) it would not rev cleanly and hesitate on steep long climbs. Plugged in the diagnostic and no codes and then the hesitancy would disappear for no reason - this started occurring from when I got first bought it.

So I then started treating it as a quirk of the engine as it ran perfect 99%of the time and never used any fluids.

However in the last 5k miles it has become a constant issue, it stopped boosting and came up with a P0299 underboost code. Put a new N75 valve on it hoping it was not a worn wastegate issue on the turbo and thankfully that sorted it. Now it would boost properly again, would start easily and idle perfectly from hot and cold. Classic signs of a faulty pcv system were apparent when removing the dipstick at idle would cause it to run off a cylinder and run really rough. In addition when accelerating it would be hesitant. Again no codes being shown. So I replaced the coil packs and plugs(even though I had changed both10k ago) and this made little difference. Replaced the rocker cover part of the PCV hoping this would be the solution but again no fix. I have noted that the PCV hose that goes down the side of the block is damp with oil but am unable to establish where it is coming from.

Any thoughts or pointers would be much appreciated as my wife is very keen to get shot but I know that with the current issue I would get very little for it if I had to sell it but more importantly I know it is to good a car to let go of.