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 ToolsCompute MD5 Checksum on your ISO.
Compare to:

If mismatch, your dump is bad (missing data, corrupted, or trimmed).