Seems to think it's 64 or 65 Pontiac
Most probably more universal GM.
https://www.kijiji.ca/v-other-auto-parts-and-accessories/calgary/pontiac-power-antenna-switch/1701400610
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)