The correct answer would be 150 psi.
If your engine is old and tired,
Look for about 120 dry and about 135 after you shoot a little engine oil or 3-in-1 oil in the cylinder.
This is acceptable, but you are getting close to needing a rebuild.
(There are a lot of 258's running around out there every day with less than 120 psi. It isn't recommended, but they still keep plugging along!)
NEVER USE WD-40 or Penetrating oil!
Those are solvents and will attack your bearing surfaces and cause scratching and galling of the cylinder walls and piston rings.
You are looking for about 10% between cylinders at the rated compression.
That means 15 PSI between the highest and lowest gauge reading is within normal limits.
You can tell a lot more if you first do a dry compression test of all cylinders, one at a time, with all the other spark plugs in.
Then do a wet compression test, the same way, one at a time.
Then do the test again, but remove the plugs from the cylinders on either side of the cylinder you are testing.
This will give you a good idea if the head gasket is leaking between cylinders.
Don't forget to do your ignition a big favor and disconnect the coil connector before you start cranking the engine over or forget and leave the key on!
That is real hard on the coil and module!