This is Tony Bailey, who is staying with us for the war."" Thus was seven-year-old, middle-class Anthony introduced to Dayton, Ohio, by Otto and Eloise Spaeth, the couple with whom he would live for four years--as one of 863 English youngsters transported and placed in US homes by the American Committee for the Evacuation of Children. And, though there is a built-in drama in the basic situation here--wartime family separation, transatlantic culture shock--the chief charms of this slim, low-key memoir derive from the very specific allure of Tony's host family. The Spaeths, you see, were hugely rich, quite Catholic (the reason for not-so-Catholic Tony's placement with them), altogether impressive; and ""Tony B.""--so-called to distinguish him from the Spaeths' own young ""Tony S.""--quickly felt the benefits of their truly classy life-style and quietly rigorous morality. Splendid dinners with servants and etiquette. . . but universal in the ordeal of no-dessert-unless-you-finish-your-vegetables. A basement full of mechanical wonders (Mr. S. was an inventor-entrepreneur who'd made his fortune in malt extract). Summers on Cape Cod or at camp, with the beauty of nighttime lakes (""Wonder of the sort that hooks one forever after""). Helping Mr. S. with the hanging of a Gauguin or a Braque--or, more important, seeing his eyes sparkle as he looked at a 14th century Madonna. Dating, on Halloween, to trick-or-treat up to Orville Wright's house (he gave the boys silver dollars). True, there were some lows--increasing discomfort at Sunday mass, losing a bee by spelling ""neighbor"" with a ""u""--but, overall, Tony B. had a glorious time in America, retaining thereafter a sense of divided loyalties. And though Bailey's cool reserve keeps emotion to a minimum, the leisurely evocation of minute details does accumulate nicely--in the very slight yet very appealing record of a lucky boy's four-year field trip into another sort of childhood.