Well, I finally ordered the Laminova oil cooler, take off plate and remote oil filter parts from Think Automotive last week and they arrived ready for me to pick up on my trip to the UK next week. When I'm back I'll book the car in with Jorrit at Auto Forza and ask him to fit it all for me along with some custom length hoses. I'd do it myself, but I just don't have the facilities unfortunately.
Also, I think I've figured out the cause of my stutter and drop off in performance around 4000 rpm. Contrary to what I thought, the MAP sensor in my non-ABS Ghibli is the Marelli APS-03 sensor (where as I thought it was an 06 sensor). As you can see from this link, the APS-03 sensor only reads up to 2.16 bar absolute pressure, which is exactly the pressure in my plenum chamber when the car gives a stutter. So I think it's reasonable to assume that the ECU in my car is designed to set the timing "safe" when the MAP sensor reading goes out of range.
I've set the maximum inlet pressure down to just below 1.16 bar gauge pressure now, but I haven't been for a drive yet to see how it performs. But I'll be doing a lot of driving next week since I'm planning on taking the car over to the UK on the ferry, so I can get a feel for how it's performing then.
No other news other than I gave the car a wash the other weekend... it was filthy and I needed four buckets of water to clean it!