Good work. Next time you go, take a couple of gallons of Rustoleum primer and paint 'em. No one will care but us. Make sure and wear some coveralls with "Earl" or something embroidered on the pocket, and put some yellow caution tape around the area you are working in so it will look like an official city job, and like I said, no one will care. Send me photos of the completed, fully-primed cannon and I will reimburse you for the paint and brushes.
If you really want to be proper and thorough, you could ask the city if you could do it, but like any government it will be full of cautious people who get paid whether they do anything or not, and they certainly won't want to get in trouble, so likely the answer will be no, or come back in a month after I find someone else to ask.
