If "original equipment" appearance isn't an issue, I'd be tempted to adapt a bellows from a rack & pinion steering system. They're made to flex tens of thousands of times- - - -more than a lifetime of engine starts.
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!