cy1 - 158psi,
cyl2 - 157psi
cyl3 - 157psi
cyl4 - 155psi
cyl5 - 149psi
cyl6 - 133psi
cyl5 - 157psi
cyl6 - 138psi
Checked the turbo no signs of water or water marks there is some side to side movement and also end play. I do not have a dial gauge so cannot be certain of figures.
from those figures you have a valve issue on number 6, I wouldn't worry about 5 at all.
have the valves been inspected yet ? done a fuel in port check ?
I have just done the headgasket on my rb27 and its just made over 700 crank hp and the compression varies over all cylinder from 135 - 142 psi and it runs like a peach, but mine is forged with big cams.