Actually there is no issue with picture quality.
I'd like to add the Hebrew name of David's father.
In one plaque it says Herschel Tsvi and the other one says Tsvi Hirsch.
Tsvi is deer in Hebrew. Hirsch is deer in German leading to Yiddish variations like Hersch, Herschel, Hirtz Hertz...
How Jews ended up to name a son "deer"?
In the Bible Naftali, Jacob's son, is blessed as a hind ( Genesis 49,21).This led Ashkenazi Jews to join Naftali with Hirsch or Tsvi.
One more comment on Joseph's last name. Kogan is the Russian form of the name Cohen. Russian lacks the sound H and uses in foreign names G instead.
So if you look back for Joseph's family in the Old Country, the older the documents the less chance you have to find Kogan. You'll have Cohen or Katz, a common Ashkenazi way to name a Cohen.
Best regards ,