Unidentified rear axle

[alexiskai]

I found a rear axle in an estate collection. It's very similar to an A axle but not identical. Can anyone ID it?

(Model A axle on the right, mystery axle on the left)

 

[Bob C]

16 teeth appears to be 1939-41 pass, comm overall length 32.85"

 

[katy]

Is the axle and gear one piece or 2 pieces

 

[alexiskai]

It's all one piece like the A axle.