Hi David158,
I checked the file first with the Edit>Project Info. See image, it showed me that something went wrong somewhere. There were two N-Gons, which are supposed to be quads in this model. (This was not the problem, BTW.)
What I found was a single point, completely without any connection. So, I used the Mesh>Commands>Optimize, to eliminate any unused points. (If you call up the Optimize, go to the cogwheel to get all options. After that the Error message didn’t show up again. In the image you see + and - signs, use them to find other problems; the object must be active for that.
I went quickly one time through the unwrapping, perhaps a little bit different than the tutorial, but close. See image. As I had translated the whole series eight years ago, I remembered it very well. So I hope you don’t mind to have moved one time through. You can go back with the Frontal Projection and do it for your self. If you have problems with the antennas, select them separately and use only the Seam, not the points [pin]. Just a though. It is good to check other options to get an idea about them anyway. The formation of the UV, the three parts, are arranged with the scale and move tool (in UV Polygon Edit mode), your initial un-peeled result might vary.
All the best
Sassi
P.S. the degenerated Polygons in the model will disappear with the Optimize.