Big thanks to everyone. I finally got the problem figured out. A colleague across the ocean had some time on his hands and looked at it. It was a careless mistake on my side

Early on in the script (before I changed strategies), I had two counters, to remind me what line I was on. I was assigning the wrong counter as the line number (I was off by one line) and it was pure coincidence that the text file was laid out in a manner where I was snagging a value that represented the sum of both sets of data. Chalk that one up to bad luck and carelessnes.

I did learn a bit more about hashes though from the thread, so it was definitely not a lost cause. Also learned that if you change the idea of your script, it's not a bad idea to wipe the slate clean.