Only one little problem remained since: the paper gets thrown out of the printer a little bit too fast or strong. So the papers don't always stack on top but skid off the tray. But it's not a showstopper.
It worked: used a knitting needle (handy thing) to guide the spring into place, compressed it a bit and it almost snapped into the rollerbar. Now everything works smoothely again - great. A fix of five minutes.
if you could also help me out with some pics, that would be great. i had suspected what you had described where the spring should go on the end with the plastic 'nose', but how to fix it to the roll? really hard to see there.