Horn question

[Terry Rust <trust@domain.elided>]

Slightly different horn question, when Sarah bought her 800 it came with an
IH air horn under the hood (about 2 ft. long) and an air tank up front. No
compressor, just a tank (10"x 24" + or -)with a schrader valve to fill it
at the local gas station. My question is this, (1) the horn doesn't work,
even with direct air, are parts available to rebuild it? and (2) was this
arangement a kludge job or was it some sort of option? It seems unlikely
that it is an option, but the way the frame is extended (she calls it her
"battering ram") to make room for the air tank between the frame rails
makes me wonder if it might be original.

Thanks for any info you might have.