Re: Berdychev records #ukraine
Have you tried The JewishGen Ukraine Database?
A very quick search for the town of Berdychiv (modern spelling) finds a few GRINBERG associated with the town.
When you search the database for the surname I suggest using a soundex search, as surnames often have variant spellings in the records.
Also, there are a large number of other researchers of Berdychiv listed in The JewishGen Family Finder: https://www.jewishgen.org/jgff/
Hope this helps,