Do you have any pics or more info on the springs? I remember buying a copy of Shadowgate that didn't save, but made a loud BOING sound when it was tapped, like a spring. I've wondered about it ever since.
Well, I thought it was funny! It's not springed shut, just look at the top how it's connected.
I'm not concerned with the plastic piece in the cartridge, but the two pieces of the cartridge coming apart.