I played a metal Selmer classic years ago for about 4 months because I had my hard rubber piece out to a refacer.
What I learned was that I had to change the way I delivered the air into the piece.I didn't recognize what was happening (I just found a way to play it that worked) until I got my regular piece back.
When I went to play the old rubber piece, it was like I was on another planet.
To respond to the OP: I don't think there is another piece like it. Some of the Chinese pieces on the market are modeled after it but they are far less than the Selmer. If you like that sound and feel, then the metal Selmer is the way to go, IMO.
Mike Ward is right about the tip/facings. They are a hit/miss proposition.