You will probably find the model tag riveted to the cabinet front, either behind the bottom storage drawer, or the left one. Another possible location is behind the oven door.

Frigidaire used that cabinet design from 1964 until 1980, with various control panel configurations. I'm thinking this is from the early 70's, as there was one that looked a great deal like yours in the home ec room at the high school I graduated from in 1974.

Perhaps others here can give you a more exact date, and advice about your malfunctioning clock.

Another place to look is under the burners. It could also possibly be on the bottom of the front frame. You would need to remove the lower storage drawer to check there, if you haven't already done so..