1950s 1957 Rear end carrier differential axle question. eldorado fleetwood 60 special

[Carcadillac]

Hi, pulled apart the used axle, and it has some damage on the outer peice on driver aside.  3 pieces inner washer, middle, and outside. Not sure if thats pressed in and or held in by that sides housing clamp. Seems to be a oil splash guard of sorts. the furthest away disc spins properly.  Can spin the bent part with lil force.  I do not know how was damaged but the axle from that side had newer sealed type bearing installed on it.    Seemed turn properly smooth before removing axles on both units.  Original has worn pinion bearing, swap the used housing to old axle housing.  Both 1957 3.xx ratio matching diffs eldo fleetwood 60Sp. Used" axle has 3 lines on shaft (where two inner disc washers are), and original has 2 lines.  Wondering what this part is, and if can swap the other over without loosening anything? May be able to bend the other back.  There is no play that would allow the axle shaft to bend the oil washer/keeper thing.  axle shafts are same length, angle of the picture.  In meantime try loosening the old worn diff see how peice comes out.

Behind the furthest 3rd disc", solid mount, past that is where axle splines engage/spin.  On used diff, its appears the outside seat" on it sits closer to the diff than on the original axle. Picture 1: Used 2:Original diff

[Carcadillac]

From what I can tell the outer ring is part of the center section tube crimped over the 2 washers/rings.

[Carcadillac]

Go over ring pinion contact pattern, got it from cpr end last year, idk returnable, should have picked it up and split it while there, but happen be passing through the area.  Able to bend the 2nd retainer ring back into place/form.  Also trying to figure out differential oil, Sta-lube makes GL4/3 wont corrode those inner washers on each side, not want waste $75 gear oil on a bad used diff.  Found proper sized copper washers, gaskets etc. My old housing is in alot better condition than one this came in.

[Carcadillac]

Contact pattern was correct, when reinstalling the axle shafts, certainly seems like that bronze/copper washer keeper could have been damaged when an axle bearing was changed and shaft was reinstalled, felt way can sit on edge of that washer before getting into the diff.