CREATE TABLE table_49531 ("Class" CLOB, "Wheel arrangement" CLOB, "Fleet number ( s ) " CLOB, "Manufacturer" CLOB, "Year made" CLOB, "Quantity made" CLOB, "Quantity preserved" CLOB)

Which fleet numbers has quantity of 1?
SELECT "Fleet number(s)" FROM table_49531 WHERE "Quantity made" = '1'
SELECT "Fleet number(s)" FROM "table_49531" WHERE "Quantity made" = '1'