The VIN is stamped on the tailshaft housing of the tranny, I would guess whatever you get back should still have the original tailshaft housing as it is not something that can really "go bad"
. As long as all the VIN info is still on the tranny, value would not be reduced in any way. Quite frankly, I doubt anyone would ever notice if the VIN was not on the housing...... maybe 20 years from now.... but not now. It will be in the warranty records for the car though.