I'd have to see that file for myself to know if there were an even faster solution, without manually selecting them all.  Couldn't you Shift-select the outer edge loop, then either grow from there, or use the arrow spinner next to your loop/ring buttons to step through the edge loops to the one you needed to grow from?  Select one edge, then hold down shift, and select the next edge in the loop (or ring) to instantly select the entire loop, or as many edges in the loop as possible, until it encounters a teminating ege.

One tip that I find very helpful is, as you go, assign hard edges by setting smooth groups early on in your model.  This way, you can use the Hard Edge selection feature to grab all the border edges you assigned as hard edges.

Don't forget it's often easier to select more edges than you need, and then remove the ones you don't require.  If you have more edges to select than not, then select them all, and just remove the ones you don't need for faster workflow.  Also remember your Fence Selection Region tool.  That's often a handy selection tool for getting at stubborn or hard to reach edges.

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