I have given up the idea of using a bead roller to emboss a decorative image into the firewall. Instead, I'll use the front wall from the S10 bed which is embossed with seven rectangular shapes. I cut the top rail from the wall and will use the loose piece to reinforce the edge of the wall that I cut from the floor. The loose piece needs to bend slightly, arching about 3/4 inch in the center, to match the arch of the cowl cover, so I made a relief cut.
Cut a piece of 18 gauge for the firewall and bent the bottom to make the turn into the floor. I'll have to raise the piece about six inches to get it right. Took some time this weekend to sketch some patterns for beads in the flat panel for decoration and stiffness. Thought some Art Deco-style lines might fit with the time period I'm trying to mimic. Settled on one pattern and started drawing to scale.
I used some cardboard to make patterns for the openings in the cowl for the windshield wiper pivots. Once I had them fitting well, I taped them in place beneath the cowl and marked their position. I cut the openings in the cowl and transferred the pattern shapes onto some 20 gauge sheet metal I'd bent with my son's brake.
I have been considering how to support the edge of the cowl cover beneath the windshield for several months. Yesterday, inspiration grabbed me as I pilfered the scrap pile: the A-pillar from the 2001 Malibu has the perfect shape for brackets. I cut seven one-inch pieces from the A-pillar and made some mounting plates from some 18-gauge scrap. I cut vertical slots in the mounting brackets, welded the plates to the brackets and screwed them into the firewall. The slots allow adjustment to hold the cowl cover against the bottom of the windshield frame loosely enough to allow me to slide it into place, making it removable.