Before hunting down files, understanding the nomenclature is crucial.
In short: Skyward Sword NTSCU 100 ISO = The complete, region-correct, unmodified North American retail disc image.
Once you have the authentic NTSCU 100 ISO, the "Extra Quality" comes from your emulation stack. Here’s the optimal configuration:
Use Dolphin Tools → Compute MD5 Checksum on your ISO.
Compare to:
If mismatch, your dump is bad (missing data, corrupted, or trimmed).