Well, it almost did the job you described. It hung at the "keystroke return" step. Easy enough for me to manually hit the button, but it was kind of disappointing to get so close without completing the process.
Do you have any suggestions on what I should look at to see why this might have happened? As far as I can tell I followed your directions to the letter (copy/paste code into file in the specified directory; chmod per instructions; edited "Open With" config), but I'm not really up on AppleScript.