Actually, I handed off my Nebula work to LC for Excalibur.  I just could not figure out how to connect the secondary hull to the saucer.  Not so much a lack of skill as a lack of not knowing what it should look like.  Plus, My time was and is just too intermittent for what Excal needs, so it was better to let him finish it off.
Funny, I think this Ambie is only my second canon ship.