At local fairs I always buy Parker Jotter pens if I find them for $1 or less. They are all used and often had refills made by third part companies. What I noticed they also have different springs.
Researching on internet I found that Parker today use type of spring as one on the photo. Most of my Jotter pens have it, but some have totally different shapes of springs.
Can someone who has old original Jotter springs put here photos of them? Did Parker used always same shape of spring or it was changed during the time?