Okay, here's the deal. I'm very good at spending other people's money (lol) so with that out there I will tell you what I would do if they were my fish. You do what you have to. Ok
At 10 months old, I would separate the fish. Their color is nice but they are not what I am looking for when it comes to grade A fins. Having said that, I would, at a later date, let them spawn to see what they produce. IF they produce any good Grade A fish, I'd work the line. (refer back to the KOI article I sent you.) If they produced nothing I am looking for, I would replace the fish with others or keep one in the community tank because it looks nice. I would not keep the 2 in the tank as they will probably terrorize the other fish and since you don't want them to breed, it makes no sense to keep them together.
That's how I would handle this. ( If I were still married, I'd still work the "another tank" angle with the Mrs. however.
) lol