Yeah, get the parts you need and pull that engine apart.. very interesting to see what the problem is.. Although the compression looks good it could be some broken rings on your No: 4 piston or something like that..
Can't wait for the pictures! I would have taken it apart years ago.. just start to do it, you learn A LOT! And... ASK if you don't know exactly how to do something like opening up a engine! And remember, pictures can tell more than a 1000 words so put a pic with your questions!
I ones had to open up a 300zx engine, it was a non turbo z32.. my dealer told me YOU CAN'T DO THAT! I told him "you don't know what i CAN! I brought it to the dealer because i had an accident at work and was very ill.. then the dealer wrecked the engine by making a "testride" It had a timingbeld problem..
I took it apart AT THE DEALER and repaired it all,It costed me 1600-2000 guilders. (Then about 1000 dollars..) This was in 2001... the car is still on the road today!!