Emmanuel, Peter -
I do have two of those cunning springs, both hard at work under my hood/bonnet/whatever. I also have two kidneys,but they too are occupied at present.
It's possible some imaginative research on-line might be helpful, though it's a long shot. They came from somewhere Italian, and at some point during production, Frua must have used all they had available. So they are likely rare. I do not recall seeing them anywhere else. I wonder what their original purpose was? They may well have been made for some purpose other than holding the hood open. What might have chromed coil springs have been made for? Could even have been for something non-automotive.
But they are really nice; a great detail. How many of these beauties could find a home? It would cut the cost of making them up.
Jeffrey