I have a Winchester 94AE in .44Mag and it has been trouble free for 15 years now. I changed out the rebounding hammer parts for half cock parts a while back, but that's another story
Tycer, over at Leverguns posted a list of parts that are unique to the Winchester 94 .357
If you decide to keep it, I would get it running and round up some spares. I have read of many problems with the .357 and very few problems with the .45 or .44
Here is the list from Tycer
Winchester 94 .357 Parts
Prices have changed, but here's the parts that are unique to the 357:
u346432060 carrier spring cover 357 magnum $3
u346421180 carrier spring 357 magnum $2
u341450220 carrier 357 magnum $20
u344912370 cartridge block screw $1
u346410100 cartridge block $4
u346401830 ejector spring, 44 Mag, 357 Mag, 45 Colt $1
u341850310 ejector $4
u341900720 extractor $12
u343030110 link, 357 magnum $22
Guides too. Which I bought cause I modified mine to cycle 1.85" OAL loads.
Tycer!