Yes I'm standing (bouncing) on the steel area's behind the Headlight. Rolling back and forth doesn't do it plus I'd have to reset the String Line if I moved it.
That Key Wall was in the House when I bought the place. The Old Bloke (previous Owner) used to care for his Wife when she was ill and that was what he used to do to keep himself busy. Asked me if I wanted him to remove all the Keys but I said 'no she'll be right'. It's great talking point. As far as maintenance goes I just sweep up the Keys that fall off the wall and give them to an Antique Dealer Friend. He cleans them up and has started his own wall