Here we can see what I'm starting with in regards to the interior. Using the access hatch (not see in this cross-section) as a guide You can see the placement of the deck leaves a decent amount of room underneath for mechanicals including perhaps the referenced "gravity neutralizer." I think there is also sufficient space left up front for the mechanicals of the ray cannon. The rearmost aft section also has room...for whatever one could imagine being back there. You can also see that while the interior follows the exterior contours there is most definitely a space between hulls.
What isn't seen here yet are the allowances I will make for additional "between hulls" space around the compartment, most particularly allowing some space for smallish motors of the collar of maneuvering rockets.
Even scaling the ship up a but from what it seems to be as shown by the full-size mock-up this will still be a compact ship internally. I don't even want to think of how three adventurers could endure being cooped up in it for any extended duration.