GUEST: This is my husband's grandfather's watch.

It was a watch that we actually found while cleaning out a home after his aunt passed away about two years ago.

My husband's grandfather served in World War I.

After the war, he stayed in Europe and toured a little while, and we think that's when he purchased it, possibly in France.

This watch, which is a Patek Philippe... APPRAISER: Mm-hmm.

...probably the finest watch company in the U, in the world...

GUEST: Right.

APPRAISER: ...was probably made between 1915 and maybe 1918.

GUEST: Okay.

APPRAISER: It's an early luminescent dial, and the condition is, like, untouched.

Patek Philippe, which is one of the earliest watch companies-- they started as a pocket watch maker in 1839, and they transitioned into wristwatches.

This is probably one of the first versions of their wristwatches.

This is a 18-karat-gold yellow case.

This particular watch was a man's watch.

The luminescent dial was really distinctive of Patek Philippe, which kind of set a style for everybody.

It was a ground-setting kind of watch.

Their production has never been large, it still isn't today.

They don't make a lot of watches, but they make the finest watch...

GUEST: Right.

APPRAISER: ...in the world.

GUEST: Right.

APPRAISER: This was handmade, probably one-off movements, one-off cases.

They probably only made one a day of this style case.

The condition is really, really nice to see.

Most of them have been refinished or damaged, and your watch is immaculate.

The dial's all original.

The dial's probably made out of sterling silver with the, uh, luminescence.

The dial says "Patek Philippe," and it's actually embossed in enamel.

Most of the time, when these dials deteriorate or they get refinished, the enamel comes out.

This watch has all the right characteristics.

Even the crystal's original.

When this watch was manufactured, this dial probably glowed.

You could see it in nighttime when you walked down the street.

GUEST: Okay.

APPRAISER: That's the lum part of it.

A watch in this condition, which is really rare, probably, in today's market, would be about a $40,000 to $50,000 watch, retail.

GUEST: Okay.

APPRAISER: And very collectible and very desirable.

GUEST: Wow, okay.

Awesome, awesome.

Yep.

I think there may be a fight to the finish on who's going to wear it next.