I only did materials with no textures or UV mapping. Making a fully photo realistic model would be really cool, but would be a massive amount of work.

The files Valve released are just .stp files. They are intended for CAD software like Fusion or AutoCad. The models have only one basic material over every part.

After I converted them to OBJ files and loaded them into Blender, I then created several materials based on my own Frame for comparison. It was a bit of a pain to apply all of the materials (most parts are one solid mesh), but I'm pretty happy with how it came out.