Named for the neighborhood in London that contains the city’s largest concentration of luxury hotels, the Andrew Winch Designs Project Mayfair (andrew-winch-designs.co.uk) is a line of customizable business-jet interiors intended to evoke those properties. The London-based design firm offers the Mayfair interiors for Boeing Business Jets and Airbus corporate jets. A cabin can be customized with materials such as high-gloss veneers, golden onyx, satin, leather, and Loro Piana cashmere. Prices, not including the cost of the aircraft, range from $25 million to $35 million. A Mayfair interior can feature a main living area with a dining table and a circular bar, a master suite toward the rear of the cabin, and a second bedroom that can be converted into an office or a cinema.