I would assume Polockaja is Russian and may have been chang- ed to a Estonian name, now in Tallinn(a/o 1918). Ostrov is 55 km southof Pskov(German-Pleskau going back to middleages) and was/is a big russian military base-town and I believe the Germans occupied this area in their seige of Leningrad/ St. Petersburg during WW II. The Pskov Oblast is just east of the Estonia/Estland/Ostland & Latvian borders. Pskov has some Evang./Lutheran films in LDS/Mormon databases;5 in "Kirikuraamatud, 1869-1940" site; and, 47 films in "Metrical books, 1833-1885". Check the Family Search LDS site, type in "Pskov". I typed in "Ostrov" which kicked out all Russian / Cyryllic, probably Orthodox church records and probably NOT of interest to you(German Luth.?).. Also, many Evangelical/ Lutheran records were moved to the Lutheran Archive/Museum in Berlin-Check their site on the Net!!!"Gut Viehl !!!"