IIRC, there's a bracket that mounts to the shift lever with a push-to-contact switch on it, or a switch on the shifter housing and an operating lever that's attached to the stick. Pretty primitive, but it works. They were a very scarce option.
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!