I'm in process of buying a 96 Excella 28. It has the "rock guards" and segment protectors (I've been calling those rock guards as well). This trailer does happen to have a stainless panel behind the LPG tanks, and it covers the entire expanse between the segment protectors.
The color is just slightly off, and I'd suspected it may have been customed fitted.
And, I think I'll take a peek behind all those "Protectors" just to make sure all is sound.
Take Care All