Copper plates???

They would be a mottled or variegated shade of green, with very occasional streaks of deep blue, occasional patches of dark brown (like an old penny).

You are quite correct about the long term stability of copper after initial corrosion.  After four hundred years of neglect, there would be localized corrosion penetrations were conditions were right.  Also, in the areas where panels have been lost, more severe galvanic corrosion between the iron and copper would occur on plates near the missing one. This will be visible as darker stains and ragged edges along the seams and near attachment points.

My former employer was involved in the restoration of the Statue, and I've examined a lot of copper corrosion in pipe over the years—sort of the resident "expert" there until they hired a corrosion engineer. It makes sense, since corrosion products are essentially the metal reverting to its natural ore. As a geologist, I could identify the ore mineral, thus revealing its composition—and hence what caused the corrosion.

 Thank you Ross for your concise, informed information...Really above and beyond what I wanted as the Kit is an old one but fairly well detailed.

        Also took the time to read your own pages!! Bravo sir..I work with history every day as a freelance modeller for the new 'Museum of the Warsaw Uprising' and have always had an interest in my Celtic roots and folklore.Hence the thing for Dragons Not forgetting my love for the British navy in the days of Sail under Nelson against that fascinating charismatic rogue Napoleon.

        Loved your thoughts about integrity,the media and politicians..I have oftn thought what happened to honour.

        It used to be that an Englishmans greatest possession was his honour.If he lost it the only recourse was the locked room and the pistol in the drawer...Now it's all about how big a (pension) they can accumulate by fair means or foul.Not getting caught is the watchword...

 WORLD BANK PRESIDENTS being a case in point..Dragged kicking and screaming instead of doing the honourable thing and walking out the door suitable remorseful....

       We live in strange times indeed..............

You're welcome!

Thank you for the compliments. Not going into politics here, but these are not strange times—we've been here before. To quote Rudyard Kipling:

Who shall doubt "the secret hid
Under Cheops' pyramid"
Was the the contractor did
    Cheops out of several millions?
Or that Joseph's sudden rise
To Comptroler of Supplies
Was a fraud of monstrous size
    on King Pharaoh's swart Civilians?

I had this prominently displayed in my office at one time. Just another thing that made me unpopular with some of the management…

BTW: You've just been Kipled, which is better than being kippered, but just as British…

And even further back:

O Tempora! O Mores! (Oh, the times! Oh, the customs!)—Cicero (Who was by no means an honest politician, himself. He was just better than most of his contemporaries.)