Not Matt Jefferies Daedalus

Basically it's the 2001's Discovery-1 and Daedalus hybrid, and the Daedalus class is one of the early concepts of Matt Jefferies when designing the USS Enterprise.

Believe it or not, there is actually no canon connection between the Daedalus class as mentioned on Power Play and the model ship that Commander Sisko had in his office, despite numerous references.

It's the same with the USS Republic being Constitution class, no canon connection where that ship could easily have been the same type of ship that the USS Kelvin was.

Anyways the ship was refined to include the impulse exhaust system where the ship either uses a fusion reactor or the antimatter reactor to vent plasma upwards and is deflected out where it glows red on the back there for thrust.  No driver coil assembly.

And of course the ship's gravity is from a centrifuge in the command module of the Discovery-1.  And the shuttle bay is just big enough for an NX-01 shuttle pod.

The engines do look a bit big, I know, but then again it's an early ship.

Oh, the large hatch at the bottom of the ship, antimatter pod.