Importing iPhoto saved on external HD to Photos & it's importing original file not modified version

I exported pictures from an old Mac with iPhoto (probably many different versions as I exported over the years) to an external hard drive. I'm now trying to import the photos on the ExHD into Photos (v5). I have been noticing that some duplicates are importing & when I compare to my ExHD I can see that it's photos that were modified in iPhoto, for example, I duplicated photo FileName1.jpg then cropped someone out & saved it as FileName2.jpg. When I exported from iPhoto originally, I always selected the option to export the modified file, not the original. When I open the photo on my ExHD, I see the correct photo, i.e. the cropped version with the new file name. I know that Apple has both a file name & a title which I think is where this problem lies, but I'm not sure how I can fix something that's in it's data somewhere.

This is a huge project so I'd love an easier solution than me going through & comparing both folders.