Thanks for all your comments. I've made a few modifications and re-uploaded the files. The shape of the foreward hull doesn't really lend itself to an airlock, but I've added a floor hatch in the Cargo Bay floor per Wbyrd's suggestion.
Boomslang - This was not a typical ship design for me in that I started with a 3D model "shell", scaled it volumetrically to 200 tons and then laid out the deck plans. My early Traveller days involving deck plans were spent playing Snapshot, so I tend to look for interesting gameplay opportunities rather than economics. If I were playing a game more focused on trading in the abstract, I might try to maximize cargo capacity and worry less about how the plan laid out. I could have made the galley and air/raft hangar smaller, I could have designed a single "spinal" corridor to eliminate redundant circulation, I could have eliminated the missile storage. All that tonnage adds up. That's my concern about starships designed by spreadsheet: they look good as stats, but you don't really get a feel for what it would be like to travel in them. Also, I rarely if ever take advantage of the tonnage leeway rules in Book 2. Technically I could add another 40 tons and it would still be acceptable by the rules.
A couple things regarding the belly turret:
1. I hope I don't lose my Traveller street cred by saying this, but the Millennium Falcon is my gold standard for small freighters. If a belly turret is good enough for the Falcon, it's good enough for me.

2. If I had to make a belly landing in this ship without functioning landing gear, I'd blow a nice turret-sized crater in the tarmac and settle in easy as you please. Remember: there's no problem that can't be solved by the application of ridiculous amounts of firepower. Paying starport fines and patching the tarmac has got to be cheaper than replacing a million credit turret.
Wbyrd - I agree about never getting tired of seeing new plans. 30+ years of this and I don't think I've ever gamed in anything larger than 1,000 tons. 100-400 tons is perfect for the average sized gaming group.