in reply to Hash w/ multiple values + merging

... I have the following [ill-defined] task: - Read two files into separate hashes ...

To begin with, what are the structures of the files? What are the structures of the hashes? Pondering the answers to these questions may show you a way to begin to fulfill your task. Then, write some code (as erix has suggested in the CB) to implement just this first step, and we can see where to go from there.