It looks to me like the problem is not from blogs not parsing the bbcode, but that the custom bbcodes you used on the other board are not setup on that board.
After that they should work. Since it does not look like there are a whole lot of blog entries, I would manually edit and resubmit the blog entries, the tool in the support toolkit would need major changes to work for this mod, probably more work than just doing it by hand.
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