Zenith El Primero movement ? The fact that the seconds index are separated by 5 sub-indexes means this chronograph is able to measure up to a tenth of a second, beating at 10 beats per second or 36000 beats per hour. To my understanding there's only 1 movement that beats that fast, which is the 'El Primero'
As for its vintage .... hmmm not sure, but if it's really powered by the El Primero then the watch could not be earlier than 1969, which was the year El Primero made its debut.