A couple observations on the M1:
(also see our M1 information page at http://www.armyproperty.com/Equipment-Info/M1A1.htm
1. Ensure you check the breach operating handle; not a part of the BII / COEI, but very expensive (in the hundreds of dollars, if I remember right).
2. Chain hoists for dropping the breech block --- these are expensive, and they are NON-EXPENDABLE, meaning, your Property Book Officer has to put them on order (it can't be done at the company level), and you MUST get them added to the Nonexpendable Shortage Annex when you take command.... or you might be buying them at your outgoing change of command! I think the removable periscopes may be nonexpendable, as well.
3. Do a quick check of the Class IX UBL while you're doing your layout. Different units have different standards. But you should make sure that the tanks you're checking have the standard Class IX items: Spare track shoes, end connectors, road wheels, track pads, sprockets (with sprocket bolts, hopefully!!), wedge bolts, etc.
4. MRS (Muzzle Reference Sensor): For some reason, these are missing every once in a while. You'll want to do a quick check to make sure they're on hand, and they actually illuminate.
5. Heat protective mitten: Depending how you count, there could be as many as 5 of these: One per machine gun, and one (or a pair... check the TM!) for the tank itself. Either the tank crew has them, or the armorer does... but someone better. This is another Non-Expendable item (unless things have changed recently), and is always a hassle during your outgoing change of command.
6. Related end items to check while you're inventorying or signing over the tank:
Mine Plow or Roller (check the BII!)
FM Commo (R/T's and VRC)
M250 smoke grenade launcher
Muzzle Boresight Device
Machine guns (if receiving through a lateral transfer or new issue; make sure you get these!!)
Blue Force Tracker (if applicable)