In this picture there are two grates, which is the name I use for them, I call the bottom one, the damaged grate, what to call the top one, which is not damaged and intact?
You already said it: "intact." Other alternatives include "mint condition," "brand new" (or "like new" if it isn't actually new, just in good condition), or just plain undamaged.
I would use the word "untarnished" as well depending on the circumstance, maybe not necessarily in this case though.
Untarnished meaning not dulled, or damaged.