I have a 1960 Chevy Long Wheel Base truck. It is the modelhaus resin. I painted the body several years ago and never finished building it. If you are interested in it, I can pull it out of storage and we can work out a price.
I built mine years ago, but I forgot who made it and where I got it from. You guys are correct, the 54 is the first year of the solid windshield. The dash is different as well, but the correct dash came with the kit. Another change is the door handles. 54 had push button handles, not the twist type. Another major difference is the bed rails are flat, not angled. I used the bed sides from the AMT 55 stepside truck.