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?

If you need a fabricator, Barkley Sheet Metal.

Drove by yesterday to see the AC condenser gone from its pad.

Copper lines cut almost flush the the foundation.

Looked in a window that had been used to enter the place (only one with the plywood gone and a broken pane of glass) and noted holes in walls.

It appears the electrical and plumbing have been stripped.

Called the bank back, told them what I saw, and declined any further interest in the place.

It is likely to be be a tear down at this point.

If you need instructions on how to dial your phone maybe you could ask for that, instead of whining.