Thanks for this mod. 10 years since I played this title. It's a million x's better with this mod.
Purchased required games from Steam. Followed install instructions for v063. Works great. Been playing for about a week. Randomly checked my data files. Tribunal and Bloodmoon not there. Copied them from Morrowind Data files folder to Oblivion Data folder. Started up game, went to check the files and get a message saying they're not valid. What do I have to do to get these expansions to work? Or is that not an option?
Thanks in advance!

If I understand you correctly
If I understand you correctly, in Morroblivion both the expansions are included in the main masterfile and their assets in the respective bsas. And install v64 to make bloodmoon to work. Of course that Morrowind files would give an error in Oblivion. They don't even matches the file structures nor the header. You now need to delete every files that was copyied from the morrowind directory.
Just play and the expansions quests will come to you. Don't mess with an already unstable game as Oblivion.