This is a constitution style ship using Kelvin parts. I also got carried away with this ship and added a variant with 2 long nacelles and one short nacelle. sort of a Dreadnought and Armstrong inspired.
Here is revised version of the Ships of Starfleet 2257. I have corrected the mayflower and renamed a couple ships.(Revised again on Saturday night 12-4-10. Just added some text and fixed some of the names on ships.)