I can tell that she has just been started, but I think she is off to a good start.
I've also read into the possibility the Constellation was a member of a class that was earlier than the Constitution class, but similar enough that she could be refitted to Constitution class specs, similar to how the Constitution class was later refitted completely, but still different enough from the Constitution and her sisters that there were some differences proportionally. It might explain the 1700- registries, without resorting to the idea that Starfleet couldn't think of the letter treatment in the first place.
Perhaps like Tobias Richter's Saladin class, perhaps early vessels used or were to use parts shared with the later Constitution class used parts similar to those used by the Kelvin. Maybe the Constellation, Eagle, and their sisters originally looked like MadMan1701's Constellation, before they were as they appeared as sister ships of the Constitution and Enterprise?
Maybe during this time, Starfleet tried to use hulls for as long as reasonable if they could be converted using a reasonable amount of time or resources, or if a ship had a distinguishing enough career?