It almost looks like a prototype GS Type 1 by looking at the color of it.

Asuza, California
https://maps.app.goo.gl/yPF9G7yW9WUCBiYG7
However, according to a railfan one was since been replaced with a WCH E-Bell, but interestingly enough the line seems to be "Out of Service" since there's a red flag on track. It may have been stolen?

What you're seeing is the adaptor for the bell on the second link. RACO Bells have a 4-inch base just like 1st-Gen Safetran M-Bells have. Looking at the second link, the mast is thicker. Adaptors were used for bells that have 4-inch bases since they can't be fitted on thicker masts.