Hey, thats a nice rendering! It wide, but that is a good thing, as you can see two variants of the same class. And I'm not to worried about the missing port side nacelle on the Mk-I Nova. It could be that we just can't see it from this angle.
We actually don't know when the Nova class like the Rhode Island began to receive upgrades. It could have been as early as after the end of the Dominion War, in the last years of the 2370's, or as late as the early or mid 2390's. Personally, I believe that the upgrades began in the early-mid 2380's, when post-Dominion War upgrades and refits began to go into full swing, though it could have also been in the beginnings of the 2390's, when Starfleet most likely be trying to equip Quantum Slipstream to what ever vessels would have at least some sort of compatibility.
I think it would have been no later than 2385, because the Nova class apparently gets another series of upgrades and refits in the 2400's/STO era. It would make more sense for there to be a 15-20 year gap between the upgrades.