How I would try to do this is to first make copies of both files. Then I would use the file that you had done the exterior changes and schedules in as your base file. In the base file delete all of the elements that had changes done in the interior elevations that you want to bring over. Select all those changed elements in the second file and paste into the base file.
You will probably have to regenerate the interior elevations and add back in dimensions that were deleted in the base file.
If on the other hand you don't have time for that and need to get the project out the door you can bring in views from one of the files into layouts in the base file to do your publishing and when you have more time do the merging of the model info.
Cheers,
Gerald Hoffman
“The simplification of anything is always sensational” GKC
Archicad 4.55 - 27-6000 USA
2019 MacBook Pro-macOS 15.0 (64GB w/ AMD Radeon Pro 5600M GPU)