(*1)
First Korea was not signatory to the Treaty. In fact the allies wouldn't even let Korea become involved in the negotiation process. Korea was just an observer.
Second, the Rusk papers were confidential memorandums. None of these opinions ever saw the pages of the S.F. Peace Treaty.
Third, American was just one of 49 countries that signed the S.F. Peace Treaty. The fact America excluded Liancourt Rocks from the treaty shows the allies hadn't reached a consensus on the islands.
(*2)
The Allies wanted Japan to have Liancourt simply because they wanted a "friendly" nation to have the strategic rocks (Japan) rather than a nation that was in dire jeopardy of becoming a communist enemy (Korea)
San Francisco Peace Treaty was NOT based on Allied Commands study of true historical ownership of territories. The decisions were reached on what situations best suited allied strategic interests