I'm looking up at what was once a series of 20 foot high downspouts, the lower 10 feet of which are gone. Copper of course, 1925. The building is a National Landmark.

The options all seem bad for replacing this:

1) Copper: it will just get stolen again
2) Plastic: not historic, would require painting the existing copper to match. Plastic is not worth stealing, which in a way is good.
3) Aluminum or Galvanized in weathered copper color: it's just not the same, and would corrode at the interface point
4) Copper Plus : no longer sold to the gutter trade. And besides they'd steal it anyway because it looks and tests like solid copper.

And even the metal fabricators in the area recommend against copper (the downspouts are not a standard sizes, so need fabrication).

The building is in California where Business and Professions Code 21608.5 requires scrap dealers to take a photo of each person, truck and load of non-ferrous metal... and then delay payment by 3 days. The end result of which is that the legitimate scrap companies bear a transaction cost, and the fly by night operators fly by night.

Are there others that have struggled with this issue?
Where did you end up?

Here is a link that might be useful: Copper Plus