Yes to both... and Stonehelm and Oakenshield are the same person wink.gif
Actually, no, they aren't
Oakenshield: The King of Durin's Folk who led his people to reclaim Erebor from Smaug; slain in the Battle of Five Armies.
Stonehelm: The surname and title used by Thorin III, the son of Dáin Ironfoot. He became King under the Mountain at the time of the War of the Ring, when his father was lost in the Battle of Dale.