I am removing the interior of my car in preparation for the roll cage. I am working my way down to the sound deadening so I can hit the stuff with dry ice to make it easier to break up.
Today I removed the seats and the remains of the carpets. Underneath the driver side seat, there were a few pop rivet remnants pressed into the sound deadening material. Underneath the passenger seat, there were a bunch of fender washers in the space between the outer seat base structure and the sill. They were held in place by dried paint from the original painting of the car. Some of them were partially painted in that reddish primer color and the rest painted the exterior color. Not the worst thing to find, but still kind of sloppy work.
At least it isn't as bad as some 70s GM cars where the workers would leave apple cores inside the door.
alan