I seek guidance on which modules to use that work in python3 that can achieve this effect.
Pandas is definitely your best bet.
03 - Lesson: - Creating functions - Reading from EXCEL - Exporting to EXCEL - slice and dice data
04 - Lesson: - Adding/deleting columns - Index operations
http://pandas.pydata.org/pandas-docs/stable/tutorials.html
Here's how to merge the separate files into one sheet: Import multiple excel files into python pandas and concatenate them into one dataframe
Here's how to delete rows: Deleting DataFrame row in Pandas based on column value
Here's how to delete duplicates: Remove rows with duplicate indices (Pandas DataFrame and TimeSeries)