You probably have 3 choices, You can paint them silver, you can spend hours doing them by hand like Joeking (nice job though) or you can spend £20 and send the bottoms for vapour blasting, sit back and have a beer while someone else does the hardwork

I have just had a pair done, spent 5 minutes with a scotchbrite pad to get the grain and then laquered them. They look pretty close to the original finish to be honest.