Hi!
I do a lot of scale modeling. There is a self-adhesive foil metal sheet produced by; wait for it... Bare Metal Foil
http://www.bare-metal.com/
It's pretty easy to work with. Just cut it into strips to go around curves, like on a helmet. Burnish it down with a q-tip or tooth pick. Use fine sandpaper along the edge so it gets really thin before overlapping with the next strip. Sand that one too, so you can get rid of the hard edge. Polish with metal polish and you're done!
Other things you can try are HVAC metal tape found at Home Despot, Lowes, etc. Use the same method above.
Bare Metal Foil makes adhesive for their foil as well. Got some shiny aluminum foil in the kitchen? Use the adhesive on that. Works great! I've seen metal finishes on 1/48 scale aircraft done with household aluminum foil! Sound absurd to me at first, but the results are fantastic!
A few years ago, I read in Fine Scale Modeling (FSM) of a guy who would chrome model parts. Not sure if he is still in business, and I'm not sure if he could do something as large as a bucket. I could look up the article for anyone, or you can ask FSM directly.
Later!