Unfortunately, there are no known birth or marriage records from Ostrog (modern Ostroh, Ukraine).  The Regional Museum in Ostroh possesses a portion of the 1886 Revision List (census). To our knowledge, it has not been digitized.or indexed.

I'm VERY late to this but the portion of the 1886 Ostrog revision list that survived has been indexed by Vik Chymshyt and is available at: https://www.tkfgen.org/names_ostrog.html Contact Vik for information about access.

Steve Toub

stoub@...