I'm certainly not as experienced with Willys as BW and all the rest, but from my other engine experiences, I'm confused why you couldn't just bump the engine in counter rotation direction via in gear rocking the vehicle, or turning the crank backwards, to take the "friction/pressure" off of the drive/flywheel engagement to allow the Bendix spring to retract the gear? Is the alignment too tight possibly, or the drive set too deep? Does Bendix engage and retract smoothly off of the engine? Just suggestions I would check for before "starting the engine" and possibly finding a "starter drag" while running, but that may be just my thinking with only my one time Willys experience. I installed a "Landrover gear reduction starter" on my L-Head that required some "fine adjustments" with the spacer plate to smooth the operation. Just offering 'food for thought'. Good Luck!