I think you must have one of the switches with a little tang on the bottom. All the way counter clockwise is lock. The key can be removed and the ignition is locked. (Tang to the right) Center position is off and the key can be removed. In this position the switch can be turned clockwise to on with or without the key. (Tang to the left)

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.