Examples of the correct seat in the 1964-66 Chevrolet deluxe cab are shown below.  The original brown insert material is almost impossible to locate however our two examples are so close!  The most original seat is # 1.  It wins the show!  However both are excellent examples of how they looked about 55 years ago.

Notice in the photos of this optional deluxe seat (part of the deluxe cab package) could be obtained on either the big or small rear window cab.  Under the upholstery covering the under padding of the standard and deluxe seats are not the same.  This top of the line deluxe seat described in the Chevrolet Sales Brochure as a full-depth foam cushion and upholstered with vinyl in red or beige depending on the choice of exterior color.

#1
Test

#2