First Stabs at Modeling Outside of Low-Poly

I know that this model probably have a strong smell of noob to them but they are my first tries at modeling for photo quality instead of low poly models for games (in Unity 3D). The model is something like a Mark I tank from WWI and it’s rendered in pov-ray. Could use advise on reducing faceting artifacts and lighting and anything constructive granted it’s my first attempt at this type of modeling.

Second go-around - added bolts/rivets; started on turret; removed back antennas; expirementing around with AO, not very good at using it alongside normal lighting

Third pass - more rivets/bolts; different lighting environments; added lights to tank; added antenna