Jeff,
Does it make noise? If it makes noise, the rebuild will be mostly a clean up.
There are writeups from owners rebuilding their own, plus some internet sites that walk through a rebuild of an old horn. I just recently rebuilt one I bought at a Reunion I attended. No manual, just a slow methodical disassembly.
They aren't terribly complicated. My biggest hurdle was cleaning it up but once that was done the reassembly process was not bad. I was fortunate to take a lot of pictures during disassembly to aid my lack of memory.
I notice from your profile, your next door in the Peach State. Can you post an image of what you have?
