Ray Cumming's The Exile of Time, in its first paperback appearance (Avalon hardcover was 1964.) Since I haven't read this - I'll have to quote from the back cover:

When a girl who said she had been kidnapped from the year 1777 appeared in modern New York, she was either deluded or the victim of an incredible time-spanning plot. And when it turned out the strange man with a mechanical servant who had kidnapped her had been seen in other centuries, it becomes clear that a super-scientific plot was afoot that must reach far into the unknown cities of the future. Serialized in Astounding in 1931. Introduction by Robert A. W. Lowndes (reprinted from the Avalon hardcover.)