Sorry, Daren, a bit of too early and too little coffee. I completely misunderstood the original situation as I had missed you migrated machines as well as storage locations. However, the basic gist of the situation is still the same. Roon is seeing any files in the new internal storage as new.
The situation seems to be similar to this thread: How to migrate music data? [resolved]
Since you might need to do another backup of the old Roon and restore, you might try this first,
Disable the current internal storage location by clicking the 3 dots and choosing DISABLE.
Then Edit the original storage location and when get that blank screen you posted, Choose Add Network Share and then add \\ROCK\Data\, like I have done on my ROCK build
And then browse to the music folder and select it.