No 8

A few years ago I found a lump of iron in the soil. Curious as I am, I brought it home and started with the process of getting rid of old dirt and rust. Although it looks much better now than from the beginning it still looks like something that most people would throw in the garbage. But with patience and vinegar baths, it should be fine again.
What it is? It is a hatch/door to an old wood stove.