I'm not entirely sure why they made it in two pieces, maybe it was because it was easier to manufacture em separately and then weld the pieces together, but it does provide a slight change in sound. The intended tuning of the 1L is C, but sandcast 1L's play more towards a B, or somewhere in between. They sound more pleasant to me, but I know some people who prefer 1pc over 2pc.
@@z0rzx362 Back then, the 1L bell was in it's infancy, so it was easier and more cost efficient to sandcast a 2 piece 1L bell instead of developing another diecast mold for Simalex (Nathan AirChime's diecaster) to make specifically for the 1L.