Where did this spring come from, and how can I put it back?

This printer was having paper jam after paper jam. I would simply open the back and pull the sheet out as instructed, but the last time it jammed, the paper was too stuck and tore. My dad ended up getting it out (turns out there's still a tiny bit left in there: any tips?), but as he did so, this spring came out. He says he didn't unscrew anything, but the back was open and at some point he accessed the underside (above the tray).

Photos below. Thanks in advance to anyone who can (or tries to) help!

Update: an identical spring came loose and I grabbed it. It came from maybe 6 inches deep. There's a plastic piece 2-2.5 inches wide that is now loose, which can be pushed up on both sides. I can't get my phone camera to focus that deep, but I have a picture of a prying tool lying passively under it and then another of it pushed up, where you can now see some light:

So we're going to try to take the printer apart.

Second Update:

It was indeed Paper Guide Upper Right.

Unfortunately, poor little Paper Guide Upper Right is broken:

Bonus image of the culprit:

Big thanks again to @oldturkey03! My hero.