see if the inside egge of the ring gear is > 1.33 deep off the trans/engine mounting plane, then pry out the pinion gear of your old suspect starter and see if the tip of the gear projects out to > 1.33. If it does, your pinion is 'getting out' there. The "button" is a non issue as it doesnt contact the ring gear nor the end of the pinion housing. Its limited by something internal, not the button. Just food for thought if you ever get in there again.
