Think about the whole thing in a purely mechanical sense.
If the gear is the same diameter with the same number of teeth, that have the same tooth form, what other things will stop you using it?
The only other things I can bring to mind is are the tapers the same and is the sideways tooth mesh correct.
If all these things check out there is no reason why you can't use the gear but you should check the tooth backlash through a complete revolution of the gear once its all fitted up
Also make sure it doesn't foul the inner and outer cases at all.
I thought the only difference was the three puller holes in the gear and that these were introduced to stop people damaging the cases trying to pry the gear off.
If you were to fit the gear I'd be getting those three puller holes put in because when you need to remove the gear at a later date, no holes wouldn't bear thinking about.
Peter Thomson, a.k.a. Tommo
A.M.C.A. # 2777
Palmerston North, New Zealand.