A top and bottom piece of tooled leather will be stitched together over this seat pan with lacing along the outer edge.

The underside of a "La Rosa" seat pan, which features its easily-identifiable brand name logo riveted in place. 

This bottom piece of leather is secured to the seat pan and held in place by large washers and nuts. It will later be stitched together to the tooled top piece.

Cowhide leather and related materials come in various thicknesses, and is often stored in roll form. In center,  a roll of closed-cell 1/4" thick padding, used as cushioning for seat pans.