UPDATE - The engine issue has been found. It is weak valve springs. The low compression was caused by the valves bouncing and eating into the valve seats. The valves I had were new genuine Toyota valve springs.
If any of you are going to build a high performance 3SGTE, you MUST buy stronger valve springs, or the same thing will happen to you. My combination of oversized valves (1mm) and higher boost, is too much for the standard valve springs to handle.
I have ordered a new set of Supertech valves, a new set of stronger Supertech valve springs, a new set of piston rings and new main and conrod bearings. The beast should be running again soon!
I have also bought a Haltech ECU (E11V2) and an AIM MXL Pista dash to go with it. I'm not going to put them in just yet though will bench test them both and set them up as much as I can before putting them into the car along with my turbo upgrade that I will do sometime next year, funds allowing. I haven't bought the turbo or any of the other physical parts yet, though at least I now have the Haltech and dash!
The car will be ready to rock at MR2WPC in January.