I like the diagram of the Pytheus Class with the Laser Turrets and earlierr secondary hull.
My son keeps mistaking it for the Declaration Class, which has its engines mounted ala the TOS Hunt, Victory and Ptolomey Classes.
I kitbashed a Declaration a long time ago. The Pytheus diagrams I've found all lack detail of the engine mounting methods. I would suspect it might be the same as the Viceroy Class medium cruiser, which has the same engine arrangement but mounts a half sized secondary hull under the saucer rear.
I would presume that the Nacelle Flush Vents would be under the saucer, as the engines don't have pylons. A problem for textures there.
Its been on my list for a long time now.