Hi Again,
I really recommend that you do a disassembly of the mechanical parts of the Crown action. In doing this you will get a much better understanding of how things work together and what effects what. The best source for assembly/disassembly of the Crown is the You Tube Channel "Sub12Airgunners". They are a father/son team from the UK who are machinist/techs who tear things apart, figure out how they work, improve them, and put them back together. They work on the UK required <12 fpe versions of the airguns, but they talk and the higher powered versions and how they are different. In the UK to own an airgun with more than 12 fpe you need a Fire Arms Certificate (FAC) from your local Police Dept.
Below is the video of how to take apart the Crown. Look on their channel for videos on tuning, repairing, resealing, etc.
Cheers,
Greg
P.S.: I just looked at the above video again and realized it shows the Crown MkI. There really aren't many differences with the MKII, but the guys do have another video showing all the differences. I am attaching below.
Also realized that they show how to degas the rifle in another video. Really simple to degas. Take off the bottle to empty most of the gun. The turn the regulator abjustment screw a little counter-clockwise and the plenum will empty. Make sure both gages show Zero.