Try playle's site. It has a RPPC stamp box date chart. It is post 1907 for sure (split back PC) but the possible dates range after that. An AZO 4 triangle stamp box could be any time up to 1918. Possibly later if the developer used old stock to make the card.
Last edited by Exhibitman; 03-22-2016 at 06:04 AM.
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