TrekMovie always had an overview. But yes, the phasers weren't redone because they never had clean plates to work from since they didn't have the original negatives, just the original final edit on film.

CBS' original plan was only to replace the space shots. Every other change took begging & justification on Dave Rossi & the Okuda's part.

We need to have him back, but 60 episodes ago we talked to Rossi on our TOS podcast about Remastered and how they did it: http://www.trek.fm/standard-orbit/6