Hi Zarnon,
Ok, Saran wrap sounds good indeed. In past we used the "Sith Lord plastic freezer bag trick" which is basically the same.
Fill the hole with 2 part silicone (after mixing its best to have gass bubbles out of it using a vacuum pump, as Sith Lord always told us, but if you don't have that equipment try to get the gass bubbles as much out as you can by letting silicone stay for some time)
Then clean that aerea, with acetone and put 2 part silicone on that hole to fill it.
Put a strip, cut from a thin tranparent plastic freezer bag over it, with the fingers go over the freezer bag to smooth it out, and wait two hours or so till the silicone is almost cured.
You can leave the freezer bag then and you will get a smooth repair.
For your other B2 doll with the locked rotation in the wrist have a look here:
You can see where the joint rotates, its almost in the elbow.
I think you have two chances when you force to rotate it.
It may either start to rotate, or the casting may break, leaving you with another repair (replacing the whole casting in the elbow).
So, I wonder if trying to get that moving is worth all the trouble.
Maybe, once it will start to move "out of its own" due to that there will always be forces on it when you move the doll around, and thus maybe once there is enough play in it that it loosens up. Doll joints loosen up in the years.
Mytime & Helen