So this design is based on a ship that was briefly described in a book called 'Serpents among the Ruins', which I first read over 20 years ago (wow, has it really been that long?) and the description of the USS Universe always intrigued me.
I've just reread the book and I still found it really enjoyable and thought that I'd look online to see if anyone had ever realised the design and to my surprise, no one ever has! So I decided to change that.
The book is set in the 'lost era' period of 2311 and is based around the crew of the Enterprise-B. I won't ruin the plot, but basically the ship is designed to be a testbed for a new Hyperwarp Drive system.
The description given by the author is as follows:
"With a particularly wide beam and shallow depth, the starship looked as though it had been compacted top to bottom, and spread port and starboard. The primary hull, a narrow ellipse with its major axis running fore and aft, had no rise to it at its center. The secondary hull, another level, narrow ellipse, but smaller, connected to the primary hull directly, the forward section of the former lying directly below the aft section of the latter. A pair of thin struts, angling backward, connected each of the two warp nacelles to the secondary hull. The nacelles themselves were flat and wide, flaring out broadly from their midpoints aft. The two-hull, two-nacelle alignment suggested a resemblance to other Starfleet vessels, but departed dramatically from those other designs in execution."
For those who may be interested, there's a whole discussion topic on this ship and it even features some imput from the author of the book. That can be found at TREKBBS here: https://www.trekbbs.com/threads/serpents-among-the-ruins-uss-universe-nx-2999.101938/
But without further ado, here's my final design for the ship and it's main bridge: