40 banjo mixed up parts ...HELP

[Init1]

Getting frustrated. I have a 40 banjo that came out of a driving car.
I rebuilt it even with marginal axle threads but now have decided to replace the axles with better ones. The passenger side also has about 1/8" end play that wasn't there before I took it apart. The drivers side is ok.
Soooo, I picked up some replacement axles and a nice complete diff with spiders. All supposedly 40 Ford.
Went to test assemble the axles in the diff and the gears don't appear to mesh
Properly.
Spiders are 11 tooth and the axles are 18 tooth.
The axles measure 31 15/16".

What the heck do I have and what do 40 banjos have for spiders and axles? And what is causing the end play?
Any and all help greatly appreciated.