OK, boys, need some help here... This rearend is in a '36 Dodge 5window coupe. I have a feeling that its the original, but just want another opinion (or two) Thanks!
It has the slip joint instead of U-joints and the drums are on a taper with a key-way/castle nut (i would post a picture, but don't think i have one.)
See how the pinion shaft is in line with the axle shafts, not below them as in modern hypoid ge****ts? That makes it an older unit, prewar. The ball-and-trunnion U-joints and tapered axles say it's a Chrysler-built rear, so I would guess it's the original one for your car.
Tapered axles and trunnion U'joint definitely say "Chrysler" to me. My guess, like R Pope's, is that you are looking at an original.