water in rear end on 1943 b

My guess is that it had that water in there before it ever found a place to rest under roof.

FWIW, I don't subscribe to the condensation theory. There just aren't enough holes in a fully assembled maincase to provide access for a constant flow of damp air to pass through the tranny, and as such, for it to condense, the gears would have to be cold enough to condense the water vapor, and the air warm enough to hold the water until it got to the cold gears. If you take the engine which is just as old, do you have three quarts of water in it? Besides, if you take an old car transmission or rearend that is just as old, but it never had rainwater running down on top of it, it won't have .3 ounces of water in it let alone 3 quarts.

But that's just my opinion.

Frank