i run chromo axles so im no expert on a stock setup...., but i would check to see if the axle has a good contact with the differential.... if there is lots of contact, and the shaft is protuding slightly inside the carrier, then i'd say its fine.
the plastic cover is just that, a pos piece of plastic.....if you want good axle seals, get the aluminum ones.
another thing to consider is the axle disconnect....do you still have it? if so then the 2 axles arent gonna look exactly the same...
sounds like the guy broke the driver side axle (common) and went ahead and replaced it with either the 95 shafts, or a tj/xj shaft (which all have the bigger u joints)
try getting a used pair of tj shafts, and do away with the disconnect. least then you will know both are right, and only have to carry 1 spare u joint!
1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.The Cherylkee....
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover 4.6 HSE
2000 4.7 4WD WJ with a rebuilt motor.
4.3/700r4/new frame buildup (YJ)....
Years to gain the hands on experience, and offer it freely.
Minutes to gain the knowledge from the internet, and quote it just as freely.