Original Rear Axle?

I'm not sure that the rear axle in my 73 CJ5 is original.
How can I tell what it is / where should I look to be able to tell what kind of axle I have?

The reason I ask is that when I was rebuilding the brakes I replaced the old rusty wheel studs. The ones in the back had a larger diameter hole than the front wheels. The threads where the same, but not the "press fit" holes. Which leads me to think it was replaced. This doesn't have much bearing on my current build but I would like to know, if not for just ordering a new diff gasket.
Thanks

 

'73 stock should have a centered diff Narrow Track Dana 44. The cover should look like this.

 

Thank you HudsonHawk.

--------------------------------

Maybe I'm thinking too big.

What do you guys recommend to reseal the diff covers after replacing the gear oil?
Should I use a gasket store bought or just made from gasket material;
or just use gasket-in-a-tube and be done with it?

Thanks

 

Found a good thread on the gasket vs sealant topic.

http://www.earlycj5.com/forums/showthread.php?t=16952

 

I hate to keep replying to my own thread, but in case someone else comes across this later.
I found a great axle reference right here in the 'gallery' area.
GENIUS!

http://www.earlycj5.com/gallery2/v/picBank/album/axleid2.jpg.html