<VV> Unknown Carburetor Float Valve

[Ron]

I'm curious about a carburetor float valve that is on my '62 wagon.  It has a metal slug with hemispherical heads at each end which sits on top of a little wafer that appears to have an elastic insert which seals against the threaded holder.  I've never seen one like it before.  Is it a premium item or does the standard viton tipped valve work better?  There's no name or ID on it.  I also have some ball valves I could use.  Any experience here?

RonH