Where in Tennessee are you? I teach school in Nashville, and my farm is near Fayetteville off US Hwy. 64. I'd be glad to try to help you identify what axle you have. The "round" description pretty well narrows it down to the Eaton with the removable center chunk, but I can take one look and know for sure. There are a couple of oldtime wrecking yards near my farm that might be worth looking into, if your current source doesn't pan out.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!