Thank you, Mr. Shaw. That might be the best way to approach this.
I'm creating subtractions and additions for each of the three pieces to "pin" them together, after printing, so I'm discovering the modifications I need to make (or the imperfections in my design) as I move the pieces around, align them, and add iterations of them. I was curious to see if there was a way to reference back to a single source object, because it would make editing so much easier.
I'll do my best to complete my design prior to the split, because I agree with your assessment, if there is no way to have all three pieces reference the same object.