Need help with ship exterior

Hey, folks!

I do ship deckplans for my games. Right now, I'm working on a YT-1300 (modified, of course!) and I'm having trouble with two spots where several angles come together.

I work in MS Paint (down at the pixel level) and one pixel equals (roughly) one inch - forty pixels is a meter. For those familiar with Frank Bonura's deckplans at the Deckplan Alliance, that is his Red Scale.

Essentially, I have a topside external hatch on the left/port side "tube" structure. In Bonura's plans, this is near a escape pod compartment, on other sources, it's part of a docking tube.
The hatch has a raised embrasure and I'm having trouble representing where it melds into the top of the "tube" structure leading from the weapons position. I can send an image showing what I'm trying to accomplish to help visualize - I'm not doing well on my description.

I am also having trouble with a bulge on the side of the cockpit pod's access tube. This hull has a centerling pod, between the mandibles. Just behind the base of the mandibles, on the right/starboard side of the tube, is a ladderwell going down. This is in a tube that bulges out of the side of the pod.
Again, I can send an image to show what I'm trying to accomplish. On my deckplans, I can do the interiors pretty well, but the exteriors are just beyond my skills. I'm hoping someone can help me on this!

Thanks for thinking about it -