Can't get my 66 GTO out of Park
 

It is on a level surface it won't let me take it out of park. I'm trying to take it out of park with the engine running, my foot on the brake. The brake switch is operating because my brake lights work. I've tried rocking the car. Is there a shift solenoid or a way to override what ever is keeping it in park or did they not have that on that old of a car? There is a button on the top of my between the seats counsel shifter, it doesn't seem to want to go down. Any help would be appreciated. Thank you