Hello..would like some help identifying the following rear end, it is a 10 bolt and pretty sure a DANA.

Looking from back of truck:
Has two us patent numbers (2018188 and 1968818);
Has an 'A' within a circle and a '45' below it;
On other side has a '2 A' with the A in a circle and 'C30147'.

On back side (looking from front of truck):
has a '45'

On bottom left bolt there is a tag that says '47-12' and '3.92';
On another bolt has tag that says 'T'

If I jack up rear end and spin wheel other wheel rotates in opposite direction. However, blocked one tire and other one locks up...so indiction is that it is positraction. But, wonder why the old tried and true method did not work?? Any ideas.

So...I would like some help verifying this rear end.

rom my research I think it is a DANA 45 (upgraded DANA 44 with large 20 spline axle shaft( with posi and a 3.92 gear ratio. Anyways..if anyone has apaches or real familiar with old 1950s tranny's and the markings then please let me know.