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It looks genuine to me. It appears that the SN is on the right side 9 o'clock position on the movement.
I wouldn't think that it would be unusual for a movement to be in good condition in a sealed case as long as it hadn't been submerged in water. It may not be the original movement though, judging from the front side of the watch.
It does appear that there was condensation under the crystal in the past. Is that pitting on the face or is it mold? Seems like a lot of corrosion on the second hand too.