I struggled with getting the correct number of records, which I eventually determined to be how the titles were being handled. This was annoying, but once I figured it out it was fine.

I began by using the Sum tool to group the first two datasets to remove duplicates, and then joined them together. For the Comics.csv dataset I split the Issue column to remove the decimal places. I then parsed the year using \((\d{4})\) in Regex to pull the four digit year from within the brackets. then, I stripped everything from the Year onwards form the titles, which allows grouping to reduce the number of records further down the line.
then it was a simple task of Adding a # to the Issue number, removing trailing spaces and joining to the first stream, then grouping to remove duplicates.