The Shielding & Avoidance caps for Items (in addition to all of the other PoP item abilities) was added back when we were still on CVS (4/9/2008 to be specific):
http://eqemulator.cvs.sourceforge.ne...31&view=markup
If you turn on COMBAT__TOHIT & COMBAT__DAMAGE in your logs, that should allow you to see how Avoidance & Shielding, respectively, is affecting chance to his & damage.