Homemade pcp

Hi Švinius.
Many years ago there was a person, I believe he was based in the UK, who wrote a couple of books about PCPs, including building a PCP. His name was Howard Mark Buckley. The books were “The Modern Pneumatic Airgun” and “Making The Modern Butt Reservoir Airgun”...
I just made a google search and found this:
https://airgundevelopment.com/book.html
[email protected]
Cheers.