Last name Voldmanis does not exist. There is an mistake in writting. The second letter can be only -a-, as the word Wald- (Vald-) means forest. In the lutheran (=protestant) church books of Wentspils (Ventspils) there are many Waldman (Valdmans, Valdmanis), but no August nor George, especially not Voldmanis.
Marina