As a note, it turns out the Mesopotamians were very advanced in terms of military. I mean, there is evidence of them forming shield walls, phalanxes, and squares in battle!
So, onto the list of what weapons are allowed:
Pole Arm (specifically pikes, or at least their equivalent)
So, for those reading along with their B\X books, that means every weapon except for the long bow, crossbow, and war hammer.
The new weapons are two in number, being the Egyptian bladed mace, and spearbreaker.
The Egyptian bladed mace is, quite simply, a normal mace with a large blade stuck on the back of it. Costs 16 gp (or rough equivalent, I'll post about money later) and deals 1d8 damage, and, if using weapon vs. armour class tables from AD&D, uses whichever is better: broadsword or mace (light or heavy, you decide).
The spearbreaker is essentially a handle with two sharp prongs, in which you catch a spear and proceed to snap it. Costs maybe 20 gp, and requires a roll to break the spear?
Now, onto armour in Mesopotamia.
Looking at the B\X list, we find shield, leather, mail, and plate.
Here is where I'm torn. The Mesopotamians had shields, leather, copper studded leather, and bronze or iron breastplates and other such armour. My initial thought is to keep the B\X armour list as is, but swap mail for studded leather and just note that plate is essentially a breastplate and maybe greaves, over some leather armour.
That's it for now, next up: Money in Mesopotamia