Dimensions of the Kobayashi Maru were shown on screen during the test at the strt of TWOK.
So, if (and it is an if) the KM is a member of the Lotus Flower class then the design as given by FASA is wrong.
I'd keep the FASA design as the LF class and make TFVanguard's design another class, and assign the KM to that class. Seems like the best compromise.
"And all I ask is a tall ship, and a star to steer her by."
"Though a cloaking device, pulsed phaser cannons
and a full load of quantum torpedoes would be quite nice too."