Well unless you supply those vendors, and with your impeccable records, I'm sure you would know if you ship or shipped decals 'en masse' to those sources over the years, the process of elimination is quite evident and exonerates you.
You did state " I personally design ALL of the aftermarket artwork on every single decal offered to the Classic Chrysler market."
Perhaps you should add "by ECS " in that statement.
All you have to state Dave is : " I certainly dont/didn't supply all the cannister decals to the hobby over the years"