HUE, Vietnam -- The sales clerk took a big ring out of the glass display case and handed it to a curious customer.
It was an American class ring, the words "Joe Toler High School" inscribed around a big blue stone. The year, 1967, is engraved below the stone. And carved on the inside are the initials of the graduate, D. H., who wore it here.
How did his ring end up in a jewelry store in Hue, a city whose ancient buildings are still riddled with bullet and shrapnel holes from the bloody siege there during the Viet Cong's Tet Offensive in 1968?
Whatever happened to "D. H."?
Vietnam is full of such little mysteries, reminders of America's deep involvement here decades ago.
The old American military bases and wrecked tanks along the side of the road are mostly gone now, dismantled for scrap, but thousands of less obvious traces remain.
Nearly 3 million U.S. military personnel served in Vietnam during the war. And there were thousands more Americans, government employees and civilian contractors.
Hue has vestiges of the U.S. presence, but Ho Chi Minh City is a treasure trove of the things they left behind.
The military black market there still does a brisk business in purloined Pentagon goods, from rifle oil to parachutes.
A Pan Am 707 seized by the Vietnamese at the end of the war sits needing repair, in a field at Tan Son Nhut airport near where U.S. military headquarters used to be, a noodle stand between its main landing gear.
And tucked away in an arcade near the Continental Hotel, the Cua Hang Sach Book Shop offers a fascinating, though musty, variety of American books.
Among the titles for sale: "The 1963 Pillsbury Family Cookbook" and "The American Heritage Book of the Pioneer Spirit."
A book store in Hue, with a small English section, had a paperback copy of Steinbeck's "East of Eden" and the Review of Modern Medicine, January through June 1965. A stamp on the review's inside cover said, "A gift from the people of the United States of America."
Americana is a little harder to find in Hanoi, needless to say, but it is there if you know where to look.
In a building housing the labor newspaper Lao Dong, a file cabinet with a combination lock on the top drawer sits in the lobby, courtesy of the General Services Administration.
At a small jewelry shop on Hang Bong Street, a ring from El Paso High School, 1966, is selling for $200.
There is something poignant, even a bit tragic, about the American high school rings.
Did there owners ever imagine their rings would end up all these years later in Vietnamese jewelry stores, commanding top dollar?
Were they sold? Or given to girlfriends? Or looted from bodies on battlefields?
At the jewelry store in Hue, the sales clerk says the Joe Toler High School ring is selling for a million dong -- about $150.
Her lips are painted pink and on her finger is a class ring from Capitol High School, Baton Rouge, La., 1966.
Why do these rings cost so much?
"People think," Nguyen Thi Hoa says, "they are an American fashion."
Just down Hue's main street, another jeweler is asking the same price for a 1966 Paducah High School ring.
"It's made in America," says Le Thi My Kim.
Nguyen Thi Cuc, 50, runs a stationary stall on the street in Ho Chi Minh City near the French colonial central post office's main entrance. The Bic pens for sale still have Bradlees price tags on them -- sent back to the city, once called Saigon, by Vietnamese in America.
Mr. Cuc's stall is situated at the top of Saigon's most famous avenue. It was called the Rue Catinat under the French, Tu Do Street under the Americans.
"Tu Do and the adjacent streets," according to a 1969 travel guide on sale at the Cua Hang Sach Book Shop, "have broken into a rash of cavernous bars, protected by wire netting and furnished with juke boxes. . . ."
Today it's called Dong Khoi Street and the bars are gone, replaced by shops catering to foreigners. They sell antiques, Vietnamese lacquer and incredible collections of Americana -- war medals, old Army watches, GIs' cigarette lighters and, of course, high school rings.
And then there is the military black market, in the same part of town where it was during the war. This is authentic, vintage government issue, the best equipment American tax dollars could buy.
There are hats, helmets, socks, packs, picks, boots, canteens, fatigues, ammunition belts, gas masks, first-aid kids, flak jackets, even special pressurized "anti-G" pants worn by fighter pilots.
One vendor specializing in pilots' jackets pulled out a box that contained, according to the instruction booklet, a "flight protective helmet SPH-4." He wanted 400,000 dong for it -- about $60.