The 1958 Chevy school bus I rode from 1960 to 63 had a switch identical to that. "Run" was the center position. Left was "off and locked". Right was "off- - -unlocked", and the key could be removed in either "off" position. In order to access the "off/locked" position, the key had to be in the switch. In order to turn the switch with the key removed, there was a pigtail-shaped handle below the key slot. I believe I've seen that switch listed on the Rock Auto site.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!