The way I have always handled "finding" or "locating" spells is that the spell caster must have intimate knowledge of the item, or type of item, to learn exact locations. The less the caster knows about the item, then the more towards only knowing the direction towards an item. And that is provided the item is within the spell's range. If there is no such item within the spell's range, then nothing. The spell and PPs go poof.
For items of power, such as the Cloak of Invisibility, I give them an RR using the level of the highest level of spell needed to create the item as the item's level versus the caster's level. If RR succeeds, then the spell and PPs go poof. If RR fails, then all the caster gets is the direction towards the item. Again, this is if the item is within spell's range.
Always, I have NEVER allowed the spell caster to know the exact location of the item, unless it is a normal mundane item such as a hand mirror. I have always all those types of spells gave was a direction, and possibly a distance. All dependent upon how intimate the caster's knowledge is for the item.
More examples. If the hand mirror belongs to the caster, then s/he will know direction, distance, and exact location. If the hand mirror belongs to someone else, then the most the caster could get is a general direction and general distance.
However, if you are the GM, then it is your interpretation of the spell description that counts most. Hope helps.
rmfr