According to the Red Book Information Guide to Brooklyn 35th edition, (1933) Osborne Sreet ran from 1582 East New York Avenue south to Linden Boulevard. 30 Osborne Street was between #9 at Liberty Bgn and #57 at Glenmore Avenue. The next block was Pitkin Avenue.
It looks as though that area is now Howard Houses, a large housing estate in Brownsville, with no through roads. The Red Book shows East New York Avenue running from Liberty Avenue to Osborne Street to St Marks Avenue. Liberty Avenue no longer intersects East NY Avenue.
With respect to David Oseas and Steve Morse, Osborne Avenue was in Brownsville, a long way from Ocean Avenue, which begins at Empire Boulevard at Prospect Park.
researching BORGER, BIRN. SCHANZER, JACHZEL in Galicia