Girard Perregaux, cal 21(19 363), automatic, Gyromatic, 17 jewels, incabloc, sweep second. (different rotor fixing)

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Girard-Perregaux_21_19

gp_2119363gp_2119363A