According to the Bioware site, you don't need to reinstall any SOA patches before installing TOB - as the fixes are included in TOB. If you already have the SOA patch installed, the TOB files will just write over the patch files.
So in other words, just go ahead and install TOB whatever version of SOA you have.
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Time is an illusion. Lunchtime doubly so.
Epona of The Laughing Hyenas