The following text from Aviation Week is not unique to the aircraft
pictured:
09/22/1969. Prototype Cessna 500 Citation six- to-seven-seat twin
turbo fan business aircraft was evaluated for flight characteristcs
during a first trip aloft September 15. The aircraft reached a
maximum speed of 225 kt (259 mph, 417 kmh) during the 1-hr 45-min
flight.