The main thing with this ship was getting everything to fit. It is one of the rare one is that as far as can be determined the stated size matches up perfectly with the image. Unfortunately putting the rest of the required features into the hull meant taking some drastic measures. The bulkheads are much thinner than on normal couriers. Note that this is the internal bulkheads only, the out hull is actually stronger than most. This would tend to mean that the walls would wobble a tad.
It is also INSANELY cramped. The access way is so small that the chubbier members of the galaxy would have difficulties getting in even if they tried to do so sideways. The living area of the ship is by necessity made out of alterable furniture. The upper two bunks fold up allowing the lower two to be used as improvised couches. The table with a holopod generator retracts onto the floor when needed. Access to the cockpit is via two rail mounted chairs. The crew sit in these, the pilots chair swings out, and then down to the command consoles, then the navigator / weapons operators swings out and ends up behind the pilot, with a control board hinging down behind the pilot chair. Each chair features 'active restrictive measures', meaning it will force your body into a position where you'll fit into the small space available.* It is therefore more or less impossible for the pilot to leave their position if the navigator / weapons guy is in place. This becomes really exciting when the engines get blown off and the ship is barrelling into an asteroid field at flank while the navigator sits stone dead in the back. Prudent Helix operators would be fitting additional controls to the forward position to control the rear seat.

Below is the exterior, THEN as a special treat another interior with added cool functions when you hover the mouse over it, followed by followed by the usual interior, which you can save.

* Incidentally this is one way in which Russian ejector seat design far exceeds the West's best efforts; part of the ejection process is having your body clamped into place, and your arms, legs and head are similarly clamped into a position that will both provide the best resistance to ejection stress and ensure that no part of the body will hit any part of the airframe. The seat then fires a two stage rocket which features a mechanical initiator that propels the seat first away from the aircraft at very high speed, and then further increases altitude on a slower burning rocket. That means it can fire quite happily at zero altitude and zero speed. It does all this is less time than it takes for the zero zero to fire.