Hi Garet, you've got some curve objects that are sitting right on the same spot as the surface edges - you will need to select those curves (which probably were used to trim the surface) and either delete or hide them to get them out of the way since they are preventing you from selecting the surface edges.

If you deselect everything and then move your mouse over those edge areas you'll see that you can select the curves there and then delete them. Or you can hide them using the Scene Browser, go to the Types section in the scene browser and then if you click on the eye icon next to the entry for "Curves" it will hide all curve objects.

Also the edges are broken up into a couple of different segments, you'll probably need to select those and run the Merge command on them to combine them together into a single longer edge before you do the Blend:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#merge

I've attached a version where I've done both of those things so it's ready to blend.

- Michael