The length I went with for the ships is from the Stargate wiki, so it should be correct.
Not really, the wiki themselves acknowledge that their own given sizes (which are taken from supplementary material, not from the show) are wildly inconsistent.
And that's exactly what I did PlutonianEmpireOpen the avatar.sc file, and change parent object from "polyphemus" to "coeus", the planet's other name. Thats what I did, and it worked.