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).
doors got only a slight curvature and won't straighten as its like spring steel now. I could try heating but I think it might do as is. Still cleaning so will assess once done. Thanks all the same.