I find a lot of WWII things here too in Okinawa, I am not much into it the WWII stuff anymore.. I try and avoid the battle areas because all the brass and bullets and Japanese stuff is not as good as German stuff!

I Like the older stuff! Coins and things from 800's to 1700's! I don't keep any of the bombs! HAHA!...I leave them where they are or turn them in!
I do work near some tombs, but I don't break into them to see what is inside and then call the archaeologist and say look what I found! .... I would be hung out to dry! I have found a lot of places in the jungle where there are human bones that may have come from some of the older cave tombs..not sure how they got thrown out or why nobody picks them up, not my business, not my country..My wife's,,ha ha I have worked with the archaeologist here and marked spots on their digs where i hear metal on my detector.. Mark them with chop sticks ...ha ha

That was a lot of fun and some of them where bronze coins. The head guy even made me a copy of their coin book! I even showed them part of a samurai sword that I found at a castle site and the younger guy wanted me to turn it over ,but the older guy said I could keep it

They took a picture and made a size sketch and went their way!
I would say it would be ok to hunt around these areas, as long as you are not looking for headstones and then digging them up, but if the government says go for it! Then do what you feel is right? I would think you would have a lot of people in Russia digging up graves everywhere! Does it depend on what country they belong too and if there is a name on the headstone?
It is hard to believe that Russian Archaeologist would trust everyone to dig up aceint sites and have them give them a call if they find something valuable. I'm sure it was us on a trip to Russia and was doing this...we would end up in Siberia!
You never know!
Anyway, Nice finds but not sure about right or wrong of everything! We all need to be careful on how far we push our hunting!
Don't want the man to come down on us hard with a bunch of new rules and restrictons.
Good Luck to all! Dave n Japan