On the delete button you have the code:
respirator_inventory.Row1.instanceManager.removeInstance(1);
The parameter that is being passed is the instance that you want to delete. Th einstances are 0 based so in your case no matter which button you press you will always delete the 2nd instance. What you want to do is find out which instance you are on and then delete that instance. You can get teh instance that you are on by using this.parent.index. So putting that into the expression you wil want to change the code to:
respirator_inventory.Row1.instanceManager.removeInstance(this.parent.index);
Paul