OK, so I was looking at my Monarch last month and saw the part number that is printed on my radiator block leads to this on NewEgg:
https://www.newegg.com/Product/Produ...9SIA6802NB5491
which states:
Closest commercial model: Corsair H80i, also from CoolIT Systems
So, looking for something in the H80i realm, only with a dual pump package on the loop. Because the pair I have here don't have any visible port or reservoir, I don't think they're intended to have any parts of the loop opened or replaced. So you would probably be looking at the parts for a multi point cooling solution like others have posted here for CPU plus GPU kinds of configurations.