For external doors most definitely yes! Copper has unique characteristics and is beautiful, like anything it depends on where you apply it.

My comment would be that fluted glass would be a bit harder to keep clean??

I don't know what its composition is, but it feels cheap and nasty. It has turned fluffy at the bottom from moisture, and the actual door itself is a strange sort-of rough texture. I would love to be able to smooth it all over with something and paint it. One step further, I'd really love to be able to make vertical lines down it to resemble the third photo I've attached - what tool(s) would I use for that. Can some clever person(s) advise me on how to get started? Thank you so much!

We have an old villa built in 1916. Most internal doors are original and have locks with escutcheons. Quite ornate. The keys have been lost though and didn't come to us when we moved in a year ago. We're looking to source keys. I've borrowed sets from our local Mitre 10 but have struck out with anything fitting. They appear to be old long Legge style keys, at least they fit in the locks. Any ideas how we could progress further? I have photos if that helps. The lock itself says Patent above the lock and below says Reversible Bolt.