Darth Piccolo said:
to add my own suggestion adywan on the close up of the at ats they always came off to me like plastic is it possible to give a kind of metallic feel?

As with adding interior details the only way would be to build a very big head to replace the existing close ups.

The bigger the head the more surface detail and weight can be shown (some of the models for Alien were huge and it really helped to get in close and convey weight but even those models had limits).

The Executor tower seen in ROTJ was enourmous but it couldn't be used to pan into a window because of the scale.

It might be possible to build a very big walker head because it's a smaller object (relatively speaking) but Ady would need more money, more time and it's a lot of hard work (unless there is an industrious model builder out there with time on his or her hands willing to donate their work to the project).