A slightly revised version
Okay, you win. I think your scale is way too big, but the overall shape here is miles above everyone else's! This is the best match by far to the blobby shape we see in TOS.
I think I may be officially logging this one into my private headcanon.
--Alex
LOL, thanks Alex
No nacelles, so, FLT impulse drive? (not really a question rather to point out that not all TOS ships had nacelles.)
Yes, in my head canon, Impulse engines in TOS are all FTL-capable.
Although I’m still a big fan of the overall design extrapolation, I have to agree with
@Albertese about the scale. Sizing it up like you have (and all the additional windows) makes it feel like less of a private cargo ship, and almost more like a mid-sized cruise vessel.
What was the reasoning for the increase in scale?
Good question
@Donny... I had scaled her up so that she could function as a cadet starship. In my mind that meant in Starfleet trim she would have interior facilities that would resemble what's in other starships and room enough to train a good class of cadets. So I scaled it up to fit two decks and a Season 1 engine room in the upper hull. The bottom hull would contain fuel and machinery and a multipurpose flight/cargo bay with doors on port and starboard sides. The ship is meant to be able to land and take-off from planets.
In civilian form, most of the Starfleet gear is removed, leaving the cargo bay below and civilian grade, automated machinery above with crew and passenger cabins.
I tried to keep her "small" relative to the Enterprise (included for scale).
I'd like to think that Harry Mudd being as grandiose and flamboyant as he is in TOS opted to avoid a tiny ship and went for something of this size or even bigger
What everyone else said about the size and the placement of the nav lights seem weird as well, I actually like the overall direction of your older version more.
Yep, I'm still playing with the nav lights. After almost 2 years? I couldn't get back in the same mindset of where I wanted to go with the older version.
On a tangent - One thing I'm kind of wondering about is whether Star Trek was doing a tongue-in-cheek reference to Lost In Space's Jupiter spacecraft with the "Class J" designation. The silhouettes of the two ships from the front bears a passing similarity with only the bottom being shallower on the Lost In Space ship.
EDIT: Corrected image. The original one I had labeled the Enterprise to Class J as a "scale" when I should have labeled the Enterprises as 1080' and 947' length for reference. My Class J is 202' long.
and I'm enjoying seeing the progress on your shuttle, Enterprise and Scout/Destroyer build outs. Good stuff! 
