Trumpeter is by far the best bet, unfotunately there is no easy fix for this one other that rebuilding the Dragon turret to fit a Trumpeter hull. The trumpeter turret is the best and has all the right details but is squashed (for want of a better word) it is the best looking of the three.
Regards,
Simon
P.S to answer your question, The Dragon Turret has serious shape issues at the rear.
The yellow line is the level the rear side should be, From top to bottom they are
Forces of Valour
Dragon
Modified Dragon (with a god awful painting disaster)
Trumpeter
Simon.