I cut the sides of the Del Ray roof just above the drip rail and laid it across the Malibu roof edges for a test fit. Left a little overhang on the windshield for the visor effect. The roof is back off and to the side now, pending addition of some ribs across the open span between the roof edges and some more work on the windshield frame to correct a high spot and two dips on the passenger side.
Got the driver's side roof edge tacked in place today. Placed the windshield frame in place with the universal attachment device - duct tape.
The fit is really good for a first-time guess. If the 55 Chevy windshield was another inch wide, it would be perfect. I should be able to bend the Malibu roof edge into the windshield frame enough to make it acceptable.
I decided to use some of the Malibu roof edge that extends past the rear of the S10 cab to make the cab look a bit more like a business coupe. I used a piece of cardboard to determine how much of an extension looked right. This is what I decided to use.
One month later... I finally got the windshield frame shaped and tacked. I included a couple of braces to hold the top and bottom pieces apart. Placed at the front of the cab, I finally can get an idea of how the windshield will match up with the Malibu windows. I am pleased with the look from the front as I think the angle of the edge of the windshield matches well with the angle of the window.
The side view is another matter. The A pillar will probably have more of an hourglass shape than I had envisioned unless I move the lower edge of the windshield deeper into the cowl.