I don't know Lily
If it's so rare, and it apparently is, ie. one of a kind, it's like searching for a missing link. In this case it's not an end stage, nor a beginning, but a time slice in the dynamics of an interaction between the dynamics of two galaxies in the process of eventual complete merging.
If you can understand that I'm probably misleading you
If you look at the ""Hoag's Object(s)"-Like" objects that we have listed in the abyss of the archives, then the more I look at it the more I feel that we should pigeon hole it there. It looks stunning, stunningly beautiful doesn't it, like that idyllic view down some verdant valley in Spring, Summer's short lease ahead. Forget it-look closer - in the struggle for life and existence the survivors after that bleak winter are faced with scarce resources; survival of the fittest. I wouldn't want to live in the heart of that maelstrom, the "The Scream" is more appropriate.
Eventually, John will give us more detail and put us out of our misery. If it's so rare, effectively a one off, then a simulation capable of predicting the dynamics of the merger would be so prophetic that it would be capable of providing time slices of the total merger, which in effect we would never see in nature, even though we observe countless millions of interactions as instantaneous interactions. We would have to hang around for hundreds(thousands) of millions of years for those secrets (was that 42 again). Does it matter?
We need another merger posted asap. I'll vote for that.