Hi Tom,
It started because the old one was rusty and I decided that it needed paint if it was going to last much longer.
But as with most things, once I got the old one off I found it was much worse than I'd imagined. Not only was it rusty but also bent out of shape both vertically & also where the reinforcement strips bolt to the chassis rails on. Or at least I'm assuming it had bent as it got thinner, I can't imagine Lotus making it like that new !
Brian