Sounds great. Have I mentioned that adding weapons was one of the first things I did with LCS? I probably have.

Some suggestions:
Desert Eagle
Think about how to differentiate from the .44 Magnum, which is the current "monster" pistol in the game so far, and is in the same class in terms of damage. One big difference is that the .44 Magnum in the game now is a revolver, while the Desert Eagle is a semi-automatic, but that doesn't have a gameplay effect at the moment. Currently the .44 Magnum revolver holds 6 shots. A Desert Eagle chambered to fire .44 Magnum ammunition holds only 8 shots, just two more than the revolver we have now, and the revolver, as implemented, has no accuracy penalty. That alone wouldn't justify a much higher price/lower accuracy penalty for the Desert Eagle. Alternatively, you could bump it up to .50 AE and have it fire 7 shots of a new, even higher damage class of ammunition. It's up to you, really, just think about how you're going to work it in.
Note that the Desert Eagle shouldn't really be illegal before gun control 1, as despite its power, the regulation doesn't start to affect pistols until that point. Consider having different levels for when the pawn shop carries it (I would have them start carrying at -1 and below) and when you can get in trouble for having it (1 and up). That's just my idea though, again, you don't have to go with it.
UZI
SMGs are currently balanced (against other automatics) in this way:
1) Lower damage.
2) Much higher initial accuracy.
3) Lower successive hit accuracy.
4) Smaller clips.
Overall, they end up inferior. Lots of drawbacks. (3) is the most brutal one -- without it, the other drawbacks would be tolerable. The entire point of using an automatic weapon in LCS is to get successive hits, and SMGs are bad at them. If implementing an UZI with even lower accuracy, my suggestion would be to remove the (3) disadvantage, and give SMGs the same, or at least a less egregious, accuracy drop-off rate.
Don't worry if reducing the successive hit penalty means that in the end, you get a better overall accuracy for SMGs across the board -- they still have notably lower damage, and I'd keep the smaller clip, unless it's in exchange for some other drawback. Just keep an eye on the assault rifle and carbine class weapons, and don't let the successive hit penalty drop below the one used for more accurate rifles.
Ithaca 37
Keep this one legal even at gun control level 2 as shotguns are now. The US Constitution has a "right to bear arms", and allowing older hunting shotguns is the way this would end up.
AA-12
Don't let the player buy this, even from the arms dealer. It would be legal, but in terms of balance, having a fully automatic shotgun is just overkill for the LCS... unless the player has to kill the enemy using it first. 
Saiga 12
This should theoretically be legal at gun control -1, but it might be easier (and more fun) to tie it to -2 anyway and treat it like the AK-47, as you suggest.
SCAR-L/SCAR-H
Whatever you set the SCAR-H power to, move the AK-47 power to about the same, and reduce its accuracy to compensate.
Crowbar
Crowbar doesn't have to have a damage bonus against doors -- merely having one in your inventory will cause you to skip the bash attempt and simply auto-break the door.