Well, if you are doing it that way, you could do that at the end of your install, since it is a minor edit - grab the tools and rebuild. You could take the .2das and edit them in at the end as well, after text comparing them to the old ones. That way you don't break all the stuff you want to add to your install.(But it would be saver and easier for you to just run it out in weidu - there are simple kit mod examples around).
The biggest problem is *which* dialog.tlk you really were working with back then. Baldurdash has changed. So if you were working with a vanilla unpatched install of SoA, vs a patched one, vs. a ToB unpatched, vs a patched, vs. the original Dorner Baldurdash, vs the newer rebuilds of Baldurdash, vs. Fixpack fixes... the reason WeiDU stuff is now the standard is it is readily undoable, testable, and most of all it floaats to your installation, thus solving this problem. If it finds an existing string in the dialog.tlk, it uses it, and if it doesn't, it creates a new one, mapping the materials into the correct place.