AFAIK, Giovanni Giordanengo is operating in a total different business as the carrozzeria I'm after.
Also not sure Giordanengo was already active in 1967.
This is the only Alfa Romeo I know (And I know a lot, but still not all, of them ;-) that was bodied by this firm.
But I still have some special bodied Romeo's from whom I don't know the creator, so you never know.
BRAKING NEWS: I found pictures of the car on the internet!