GUEST: So this tea set, it was my mother's pride and joy.

It belonged to, I think, our great-great-great- grandfather Robert Stuart.

And he is credited with finding the overland passage back from the Pacific Northwest.

Lewis and Clark found the river route, but he's credited with the, the return passage, and he was sent by John Jacob Astor.

And returning to New York, he was given this tea set from John Jacob Astor for his wedding.

APPRAISER: This is an absolutely exceptional American silver coffee service.

GUEST: Wow.

APPRAISER: You obviously have the coffee pot here.

You have the sugar, which is covered, so it's a covered sugar, and you have the cream jug.

And it's made by a gentleman by the name of William Thomson, who was based in New York and was active from around about 1810 to the mid-1840s.

And as you had said, your relative discovered what's now known as the South Pass.

GUEST: Mm-hmm.

APPRAISER: And it's an incredibly important pass.

And he worked for the Pacific Fur Company at the time for John Jacob Astor.

And what we love about this set is that it has all of the features which really commemorate the Pacific Northwest, primarily with the beaver-form finial at the top...

GUEST: Mm-hmm.

APPRAISER: ...surrounded by the laurel leaves.

And then this absolutely spectacular...

I'd like to say it's perhaps probably a wild turkey or eagle-form spout.

GUEST: Mm-hmm.

APPRAISER: It's just really beautiful.

We can tilt this back, and it says right here on the underside "Robert Stuart from John Jacob Astor, 1813."

And buried beneath it is the maker's mark, which is slightly what we call effaced.

You've got this beautiful lobed form, also, on both of these pots.

You've got this wonderful shell casting at the base.

All very, very typical for William Thomson.

He has other pieces in museums and institutions, which, interestingly, feature other animals as finials, as well.

GUEST: Really?

APPRAISER: So, it's kind of his thing.

For this beautiful silver set, for all three pieces, I would expect to place an auction estimate of $15,000 to $25,000 on it.

GUEST: Wow!

Wow, fantastic!

That's great!

APPRAISER: I believe that insurance value is going to be probably closer to $40,000.

GUEST: Wow!

APPRAISER: If you had presented this to us today with, without the inscription, it's still a spectacular coffee service as a stand-alone.

An estimate would probably be in the range of about $8,000 to $12,000.

GUEST: I really expected it to just be worth the melt weight.