I want to put some quick release swivel seat mounts onto my aluminum bench seats. The seats are solid filled with foam, and I cannot get to the bottom of the swivels to put nuts and washers on the bolts to mount the swivels. Can I drill small holes and use self tapping big screws to mount the swivels or maybe some good sized toggle bolts just working from the top of the bench seats? What are some other (better) ideas? Thanks!