Whitetiger, I can't thank you enough for pointing that out. I must have been crazy, thinking seat belts would be on the seat page. Now that I look back on it, I realize how ridiculous that was.
I found the seat belt, and it's about $109. Maybe I should look for the part I need instead of a whole seat belt, to save money.
HAHAHAHAHAHAHAHA. Whew. Made myself laugh.
Thanks for the suggestion about the screwdrivers, Jay. I didn't post that picture to show details about the part, except the lack of screws. You did a great job, picking out that detail.
Now that I know the belt can be bought, I can try to open it without fear that I can't replace it if I destroy it.