It seems the OU (Orthodox Union) logo of today had a predecessor:
"Prior to Heinz sporting the OU logo that is recognizable today, the Loose-Wiles Biscuit Co sold their kosher crackers where a complex seal featured the OU insignia in Hebrew."
Source: https://aish.com/heinz-baked-beans-are-an-integral-part-of-our-jewish-american-history/
What did that Hebrew logo look like?