Just a SWAG, but check to see if that's a temporary parking brake, like a home brew version of the MICO brake lock. I'm not sure about the function of the push button, but the handwheel looks like it might be used to apply the air brakes for locking the wheels while winching, maybe?
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!