Both OEPIAG & EPIAG were associations of different potteries put together by the Austrian Government in 1918 to promote the sale of Bohemian pottery and porcelain.  Some of the porcelain artists studied production techniques in Sevres, France.  This set dates to WWI era and while under OEPIAG, only 4 companies were making porcelain : Proschold & Co., Springer & Co., Oscar & Edgar Gutherz, and Fischer & Meg.   The name "OEPIAG" is an acronym for Osterreichische Porzellan Industrie AG" aka Austrian Porcelain Industry.  Any pottery with this mark dates to pre 1920 when the name was changed to EPIAG which existed 1920 - 1945 (WWII era).  

Pre-owned, No damage noted. Teapot stands about 5 1/2" to the opening/lid area. and is about 5" in diameter. A good size it holds about 4-5 cups. The Creamer and sugar are about 3 1/2" talll and about 3 1/2" in diameter across the body. Unpacked weight of this beautiful porcelain is about 3 lbs 4 oz but will need extra packing, probable double boxing which increases weight and box size.