It's your lucky day. I also own a Downeaster of the same vintage and I can tell you everything in the world there is to know about your question.
1. Learn to love green. It's not discoloured, its aged- a patina. Like a piece of art. Scrub it with pure clean salt water
to make the bronze go greener. Paint
your topside stripe green to match. Use red bottom paint
for contrast. Become an Irish citizen and change the boat registration
to Irish so there will be no doubt about how you feel about green. That's what I did. Green is beautiful!
2. For things you simply feel compeled to renew to shiny metal status, use phosphoric acid (brand Phospo) which you can find in the paint department of Home Depot. As stated previously, Muratic (pool) acid works, but it is a much stronger and more dangerous acid. Soak in 100% phosphoric acid and rub with bronze wool or a 3M SkotchBright pad and the oxidation will dissolve away magicly in an hour or two. Be sure and wear rubber gloves, etc.
It works great but you have only removed the oxidation. If you want it shiny you will have to polish it and that is a whole nother topic. Youl'll need to take things off the boat
and use a grinder with buffing wheels, several degrees of abrasives and patience to take it through the stages of surface smoothing just like you would teak
. I did this for things in the cabin
and it wasn't all that much work
and be sure to laquer it afterwards or you'll be doing it again in a month.
BTW--phosphoric acid is also execelent for cleaning engine heat exchanger
tubes, saltwater toilets (disolves urine created calcium deposits in the plumbing) and also stainless steel
and rust on regular steel.
Bronze is out of fashon on boats because the market is driven by newbie
buyers who respond to the shinny stainless look. But bronze is a near perfect metal for boats and a salt water environment
when strength and reliability
is paramount. Bronze does not gaul, does not self destruct with hidden crevice corossion, rarely has hairline cracks like stainles steel and will truly last a lifetime. For chainplates, turnbuckles, propellers, and the real working end of things, bronze is great.