Very interesting article. Thanks for sharing it here.You can cut down a Wolff 19lb Makarov spring. It worked for me.
http://www.miracerros.com/guns/gn_cz82_spring.htm
After cutting the spring to length, I used two pair of needle nose pliers held about 1/4" apart to tightly grip the spring near the cut end, then carefully twisted the pliers to get the bend I wanted. Took several tries to get it right, but it wasn't difficult.how did you "flatten the end" (per the article) after cutting off the extra coils from the Wolf spring?