What baseband version are you running?
IIRC, only the initial release, 4.1.1 basebands worked to apply that trick.
Here's a CWM/TWRP flashable zip of the I317MVLALJ2
(4.1.1, October 2012) modem to get you started.
As well as the I317MVLBMA3
(4.1.2, January 2013) or I137MVLUCMK3
(4.3, December 2013) to get you back to your current baseband.
Your wife's Note 2 may be a bit trickier since 4.3 has KNOX, but I'll let you look into that.
Good luck and happy holidays,
My phones: Galaxy Note II SGH-T889V (with LTE enabled
/ ext4 SD card support on TouchWiz ROMs
Previous phones: Nexus S GT-I9020A, Galaxy Gio GT-S5660M (Arpeggiomod ROM
/ Discussion, stock rooted ROM
Phones for which I play "tech support" for family and friends: Galaxy Nexus GT-I9250, Galaxy Q SGH-T589R, Galaxy 551 GT-I5510M, LG C-800G Eclypse, Motorola XT-1032 Moto G
- Level 8