Mine is an early 70's model.

Lens - 55mm f/1.7 Rokkor

They were first made in 1966 and the third generation versions were made until 1975. It was one of the first cameras to have full aperture TTL metering - correct exposure is achieved by matching a needle in the viewfinder to a circle moving with the exposure settings. The battery only operates the light meter - even without a battery all functions still work(besides the meter).