Anybody know what part this is from a steam loco ?

I've had this part for years - bought it at the old Edaville RR fan day flea market. It's about 6-1/2" long, the curved handle is a spring-loaded trigger that causes a small pin hole to open up at the top when the trigger is pulled. Looks like it held air. Any ideas ?
http://naphotos.nerail.org/showpic/?200 ... 711577.jpg

It's an antique blow gun for compressed air-- the air hose goes on the barb at the lower right. And anyone who told you it was a "steam locomotive part" was doing what this item was designed to do....

NOT a steam loco item, sorry.

Caveat Emptor.

Thanks H.F. I always thought that it looked a little small for steam engine scale, hmm. Oh well, for $2-, I can't complain !