Greg Jein also regularized the grid on the bottom and made something up for the grid on top. Both are not a nice round number of degrees. He got the phasers wrong on top as a result. I've seen several versions that have used his model as a guide rather than the original. I've toyed with rendering some of his changes for a USS Fredrickson version (the only label other than Excelsior that physical model had before it was digitized), but I just don't have the interest.