GUEST: This hard hat belonged to my uncle. He worked for Mobil Oil Company, and back in the late '60s, early 1970s, he was sent to Nigeria. He helped the Nigerian oil companies develop their oil fields. In conjunction with his time spent in Nigeria, he received this hard hat.

APPRAISER: Is that the name on the front of the hard hat?

GUEST: Yes, it is, Oliver Rufus Malone.

APPRAISER: There are other hard hats like this that are decorated with all this carving, and they're always aluminum. These are American hard hats. This one, if you turn it over and look at the lip, there's the name of the company that manufactures the hard hats for the American firms that sent them over. These guys would have them decorated up like this, and I've seen probably a half a dozen in galleries and just scattered around the country. These figures appear to be Coptic Christian marchers going around.

GUEST: Okay.

APPRAISER: And they're not of the era. Every so often, you'll see them that have oil derricks on them and that sort of thing.

GUEST: Right, right, right.

APPRAISER: But this is sort of the high art of the oil fields. And I've never seen anything else like it that comes out of the oil field.

GUEST: Yeah.

APPRAISER: Every so often, you'll see a painted one. These things are the coolest of the cool.

GUEST: Yep.

APPRAISER: There's animals carved into the top. It is a wonderful piece of art.

GUEST: Yeah.

APPRAISER: They're all over the place price-wise. Being very conservative, if this came up for sale, I would expect it to be $600 to $800 in an auction.

GUEST: Very good.

APPRAISER: In a gallery, I would think it would be $800 to $1,200. They're just fabulous things.