This is something really new for me, but I thought I'd give it a shot.
This is the Screaming Mynoch, an ancient YT series cargo transport. It has large external cargo mounts to make up for it's limited interior space.
This here is the stock version but, of course, it can be easily modified.
There. Enjoy. You probably won't be seeing many more ships from me. Too much work. Too much math.
Medium: MS paint