OK

I have a 60's Ford parts manual on a DVD that I got on Ebay a few years ago.It is pretty good for when I want to look thinks up like your stamped air horn number.I have found a lot of OEM part numbers with it.You can get one on Ebay if you want but when you do,download it to a file as it is faster to look up parts than with the DVD loaded.
Like stated these are very good street carbs and less problem areas than a Holley if you are not a carb guy and easier to rebuild.