The B'rel (and releatives) are anywhere from 80m up to 800m depending on what source you choose to use. The SFB Klingon F6 frignought is a three nacelled ship ..........
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I agree with F_W, though the mesh is fantastic, the concept isn't. Basically every configuration you could think of involving extra wings added to the B'rel design has been done. Single wing, X-wing, cross or + configuration, three wings, attack elevation, cruise elevation. Extra disruptors and the ilk. Not a good candidate for an F6 upgrade/refit, unless it's just a label on a weapon configuration. The ships look nothing alike. Considering the F6 is just D7 parts, I would think using Vor'cha parts (though no more believable) would logically follow the pattern. But I do like the mesh
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very clean and compact. + 1 for the mesh.