Hi Hugh,
Thank you for your patience and your quick reply. I am taking copious notes through here so that I don't need to ask needless questions in the future!
To clarify, I have the Sibelius 7 SoundSets shown in the attached screenshot. I just didn't have exactly what you had shown in your linked screenshot ("S7S-SE6 SoundSet 7.1a"). I wasn't sure if I needed that file exactly or if you were using a pseudonym to cover the range of what I might see in the drop down menu.
Also, Hugh and Ted: Thanks for the advice with (AU). I honestly had no idea until now!
This is a great community and I hope that someday I can be a tutor instead of a tutee :-)
--cj