my morals if I find stuff: if there is no ID, it's finders keepers... do what the police would do... take it and use it. no one lays claim on the object.
My mom once found a wallet containing exactly 901 US dollars, but it had no ID or anything else in it... finders keepers
Here in Denmark, you may legally take 10 percent of the amount of money you find IF there's a means of owner identification, ie. proof of who the owner is, else you may legally take everything.
Also, many stone age artifacts can be found here (stone knives, axes, spearheads etc.). People usually keep them for themselves, but according to law, one has to donate them to a museum, HOWEVER you may require payment for the item. Another thing is that you must report where you found the item so the area can be turned into an archeological site.
I've personally found small coins, a few flint knives and a few pieces of amber with insects stuck in them... one of the amber pieces brought me some good money as it contained both a mosquito and a fly, which is heaps more rare than finding one with a single insect inside.