Knees, boots, ...... yup, they took a pounding in the day.  Not usually from someone trying to break in to get the coins, but usually out of frustration.  Me thinks the slam switches got a few closures in the day as well.

Always worth tyring to flatten if possible.  I think you would go the skin replacement only if needed, as they aren't cheap (I think Marco's price was around the $90 mark, from memory).