Found two boxed Red Cross rosettes with the dai (大) hallmark. Inscribed on both cases was the shop that made it: Ohashi (大橋). One has additional information that I cannot make out (faded), with the exception of 'Tokyo.' That, though, is a big hint. The two kanji next to Tokyo are probably an area name, and the three below Tokyo also seem to indicate an area ('below -- '). If anyone has similar inscribed cases that are not faded, that would let us identify one hallmark. Little by little...