There are only two other files that are different:
KBVistaShellSupport.dll - I'm not sure what this file does.
loc_data.kfs - This is the KFS file that contains the intro OGG's and some PNG's. All the files in these archives are identical, except the GOG version has other language variants of the PNG's, whereas the GG version has just English.
That's it!
/C\/C\
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