GUEST: About 20 years ago, I moved to Baltimore up in Waverly, and I bought a little row home there, and these were in the ceiling of the basement, used as insulation.

APPRAISER: And how many did you find?

GUEST: I have probably 200-- lots of different varieties.

APPRAISER: You brought about 30 or 40 today, and we picked out these....

GUEST: Picked out my favorites, yeah.

APPRAISER: It's sort of a strange subcategory of advertising collectibles. A lot of people are familiar with them from subways. They were the ads that went up across, next to the ceiling.

GUEST: Right.

APPRAISER: But the first thing we've got to do is date them. And the first clue we have is the printer's code, which says "10-33," which means that this was produced in October of 1933. So all of this material seems to have come from the same year, and there was obviously somebody who worked in the trolley system who took them home. Yeah, that's what I'm assuming.

GUEST: The home was built in the early 1930s, so I'm figuring the first owner must have worked for the trolley car company to be able to get them as they were disposing of them and used them as insulation.

APPRAISER: Now, so let's start at the top. I find this to be a fascinating piece; I love that design. A piece like this, as far as putting a value on it, would run $300 to $400 for that piece. This one's a little more mundane, but it has a nice NRA stamp. So you're looking at $200 to $300 for this. This one sort of relates to the whole era of orange crate art. It's a beautiful Sunkist piece, about $400 to $500.

GUEST: Oh, my gosh!

APPRAISER: This one here has a couple of things going for it. It's a nice piece of trolley advertising, and it's a piece of advertising for one of the more popular and collectible World's Fair: the '33 Chicago. You had a bunch of them-- I just picked this one out.

GUEST: Right.

APPRAISER: This is a $500 piece. Maybe pushing to $600. The condition is nice. This one, it's a very nice colorful piece, about $300. And here's another one that helps to date it. This is from Roosevelt's 1933 campaign. And again, there's another pressure on the market: aside from being a piece of advertising, it's also a nice political piece. You had a bunch of these.

GUEST: Yes.

APPRAISER: And that's about a $400 to $500 piece.

GUEST: Mm-hmm!

APPRAISER: So if you start adding up all that other material, you'll see that it's quite a collection.

GUEST: Ouch. (laughs)

APPRAISER: The values that I mentioned are what they would fetch at an advertising auction.

GUEST: I guess I need to get them out from underneath the bed and do something with them. And I almost left them behind when I sold the house.

APPRAISER: Well, this was a very fortunate accident.

GUEST: Wow, I'll say. I really thought they were, like, $25 a piece.