A W.W. I or W.W. II vintage large breach what? A large ring Mauser? Or a Mannlicher-Schoenauer. Either way it'll be a custom stock for a hunting rifle. Not seeing any ready made Mannlicher stocks at all. Boyd's doesn't list any Mannlicher stocks either.
Custom stocks at very big time money. There's a guy Stateside(claims to be one of the world's most famous custom gun makers) who charges $1500USD extra for a Mannlicher stock.