The Quldun class appears to be modeled on the early Bird of Prey from ST:Enterprise. Which would be in keeping with Cryptic using ST:E designes that reasonably wouldn't exist three hundred years later...vbut that's another story.
Also from the ship chart, there is one design lineage that Cryptic made up from whole clots, and one "modified" from canon designs. They are:
1) Ki'Tand and Hegh'ta classes - Early BoPs with extended "wings".
2) The Somraw/Pach/Quin classes - nothing really like them in any original ST series, though they share some design patterns with canon designs. That also includes the end ship of the lineage, the Vo'Quv.
In canon Trek, the Negh'Var was the penultimate in Klingon design - even int he Mirror Universe,t he Klingon dreadnought was a enlarged Negh'Var. If you look at the whole ship chart, you'll see that Cryptic licensed a extremely limited number of ships form Paramount, then filled in the "gaps" with designs of their own. Some designs (Zephyr, Vesper) look like they couldn't get the rights to the design, so came up with a lookalike that is just close enough to bear the resemblance, but not violate copyright. Dunno why, Cryptic must have thieir reasons.