A Görög és Latin Nyelv Hang- és Alaktana (I think that translates as Phonology and Morphology of the Greek and Latin Languages) was published in Budapest in 1932 by János Szidarovszky. It is owned by exactly one library in the States, Columbia. I haven't been able to discover anything about the author yet except that János Harmatta published an obituary of him in Antik Tanulmányok, 1954. I also can't say anything about the quality of this work except that the author certainly seems to have been au courant with the latest in IE scholarship to judge from the works cited. But I can say I've held it in my hands and leafed though it. Is this the sole historical grammar of Greek and/or Latin written in Hungarian?