I don't see this going over 40k. The hope is to have four of them. Imperial tactical doctrine is to field them in pairs. Individually they don't have enough firepower to knock down each other's shields except at very close range, so they need to team up. 2 vs 2 is the goal.
Either that, or I'm going to have to do the escort ships.

I'd been hoping to get more progress done tonight on the dorsal sections, but a previously unknown type of mesh error has been manifesting, and I've been having the devil of a time tracking them down. I estimate there are about 4 polygons out of the 27k so far that aren't quite where they're supposed to be, and they're screwing things up. Why they're messing things up now and not earlier, I don't know. I've been doing some volumetric searches, and have found a few of them, but it's really hard going.
Edit1: Ok, think I've got most of them, though I suspect there may be others that haven't manifested yet.
Edit2: Good grief, smacking these errors is like whack-a-mole, you get one and three more spring up in its place.
Edit3: 3 hours later... finally, finally got all of them. maybe tomorrow I can make some actual progress on teh superstructure...