Thank you! That was it! I opened my original POW wallet and typed in console: walletpassphrase (mypassword) 900
Then dumpprivkey (myaddress) and it gave me the goddamn private key finally

Then importprivkey to my new POS wallet and there it is, all my nobles safely on my POS wallet.

Gotta tell you that I would never believed that I can get my Nobles back, so thank you very much


edit. And I'm pretty sure everything is working because it says "Minting. Your weight is 227818. Network weight is 418959937. Expected time to earn reward is 1 day(s)."