Driver seat base screws stripped

[Limbination]

Hi, I recently purchased an 08 Wakesetter 247 and the drivers seat became detached from the floor of the boat.  The carpeted base piece has about 16 screws in it, which don't all appear to be factory.  The screws in the corners are larger, and might be factory, but also may have been a previous attempt to re-attach the base to the floor.  Does anyone know what is directly underneath the floor in that area? I'm wondering if I can drill a small hole and attach some bolts/washers under the decking to secure that carpeted base? The seat also has a riser which I think may have caused the screws to rip out in the first place when a lot of pressure was applied to the seat back. If I shouldn't drill a hole and add bolts, any tips to re-secure to the floor since there are already so many stripped holes?

[PopsA22]

Did you ever find a solution for your stripped threads?