Alot of the guys over on the Vintage Leather Jacket forum do the same
water treatment to their A-2 jackets from Eastman, Aero and Real McCoys
all the time.
They call it the "Hot water treatment". You don't soak the leather to the
point of it getting the lining wet.
You are trying to wet the leather surface, and then, as the leather is
wet, you ball it up to get the wrinkles and creases that make the jacket
look nice and worn.
It also will make take some of the color out of the leather, but not to the
point that acetone does, so it looks much more natural in its appearance.
This process also will soften up a stiff leather jacket as well.
The nice thing about doing the hot water treatment process is, you can
do a small section at a time, and see the results as you work the jaket
to look the way you want it.
Also, what some of those guys do is, they get the jacket wet, and then
they wear it, push up the arms to get the arm creases and what not, and
wearing it while it drys on you will make it conform to your own body, and
make the jacket a true custom fit.
Here is the vintage leather jacket forums website:
http://cornellsurgery.com/v-web/bulletin/bb/
Flathead