Valvoline VR1 racing oil question
Lubrizol invented zddp in 1941... Still in business I think. Don't remember the other companies but there are only a couple.
I got involved with a little of this stuff many years ago when a friend hired a local oil supplier to blend a racing oil for him. This company did custom blending and packaging for smaller oil jobbers and retailers. I learned a lot and have forgotten most if it!