In my post of October 5, 2017 (https://blog.appletonstudios.com/2017/10/stained-glass-heraldry.html), there was a coat of arms in one of the three windows that was not identified, but was possibly related to the anonymous donor of the windows, who had them made for the church in memory of his mother.
Reader Ralf Hartemink (who runs the website Heraldry of the World at http://www.ngw.nl/; if you have any interest in civic heraldry and have never seen his site before, I cannot recommend it to you highly enough. I use it all the time when researching civic coats of arms) has come forward with a possible identification for the arms: the Polish family Prawdzic of the herb Szlachecki, here (image from pl.wikipedia.org):
Historically, the arms had the golden lion on an argent (silver) background, as exemplified in this redrawing from the Gelre armorial:
I'd like to thank Ralf for letting me know about this Polish coat of arms, and think that we may have made the anonymous donor of this window a little less anonymous.