I don't have the answer to your question, but here is my experience.
I needed a new shoulder harness for my old Granite Gear Ozone pack. Went to the website and ordered a small, trim size shoulder harness.
When it arrived I realized that it was the shoulder harness for the new backpacks they now make. It is compatible as in you can attach it to my Ozone pack. However it is much longer than the original and doesn't fit me well at all. So I tried to contact Granite Gear through their website to see if they have the old style shoulder harness. No response, contacted them again, and again without response. I think their website communication is broken.
They don't have a phone number on their web site, but they do on Facebook.
Phone 218 834-6157 (ext 2 Customer Service)
Called them and got a very friendly customer service rep on the phone. She went to the warehouse but could not find any old style Ozone shoulder harnesses. So I think I'm out of luck.