sofa frames

Hi bit of a long shot but we've found 2 bolts from under our 3 seater recliner sofa had a good look under there with a torch and I can't find any previous holes :mad: it's driving me nuts plus there pretty big screws so must be important. Anyone had this happen? Or know where they've come from?

I'm attempting to repair a leather sofa that sinks in the middle if you sit in that spot. The cushions are attached and still very full and plump, which lead me to believe the problem must be underneath? (broken springs or such) I have removed the dust cover underneath and I am confused to find...