I've been trying to do those cutouts, but for some reason, one side of the cut out doesn't seem to show up in renders. Not sure what the problem is. Could be an issue with the lighting of the cut out.
I wasn't sure what shape the cargo doors should be. I'm thinking rectangular. Possibly numbered. Maybe a few hull line cut outs. We'll see what I can come up with. Hopefully it'll work out.
Once I get this section done, and added the windows back in (I re-mapped the secondary hull, and I love the new unwrap much better), this part of the secondary hull will be done. After which I can focus on the registries and nacelles/pylons, and work towards getting everything finalized.