Re: Refit Dreadnought.... Question?
If, by "canon" you mean on-screen display of a ship (or schematic of a ship) in a STAR TREK feature film, to my knowledge there has never been a dreadnought revealed, other than TNG's "All Good Things..." finale and some vaugue schematics on bridge viewscreens in various Kirk-era feature films. If memory serves, a Federation-class dreadnought starship was shown on a viewscreen in the background in TMP #3, but never shown "in the flesh" and never in a "refit" configuration.
What you're talking about here is the TOS FJD Federation-class dreadnought, tho.
Related article at Trekplace.comForgotten Starships: "Canon" References to Star Trek Spacecraft Designed by Franz Joseph
(from our very own Fal Tor Pan's
Once Upon A Time....