Ah, I had forgotten that for officers, I had put the new "Exchange" button in the same place and "Equip" never becomes visible. The quickest way would be to disable "Exchange" and you won't be able to use that feature and would have to exchange equipment the "old" original way by speaking face to face.
In items.c, also disable "Exchange", then you should be able to remove/equip individual pieces for the officers:
else
{
SetNodeUsing("EQUIP_BUTTON" , true);
SetNodeUsing("EXCHANGE_BUTTON" , false); // bExchg);
}