I was quite happy with how that came out. I have done a fair amount of photo texturing in the past and it works well, but usually results in using multiple images. With these sinks, I committed myself to using one image. I wanted to keep the file size down, and not have extra textures brought into the model to confuse the user.
I did model all of these sinks off of the technical drawing, so they are accurately sized. Because most camera's distort pictures, its not always wise to model directly off the photograph and expect to get the correct size. When modeling for Google Earth on a picture, accuracy isn't as important, because people don't expect GE buildings to be accurate.
Once I had the sinks modeled accurately from the technical drawings, I then stretched the image over the model and painted it on. For the double bowl sinks, it worked with using just Sketchup's native texturing tools. For the single "D" bowl sink, the picture I had as a reference was badly distorted, so I had to take it into Photoshop and use the mesh deform tool to bend it to the shape I needed. If you look at the "D" bowl's texture in Sketchup in the materials browser, it looks "Punched"
There are some faucets that are in the 3D warehouse that I use all the time that are modeled using this same technique, check them out. They are all modeled with one texture image.
http://sketchup.google.com/3dwarehouse/cldetails?mid=2cb68736970f2e3c4a5d5b6d2c205843&prevstart=0