So you mean Don Yenko ordered his sYc's one at a time?
Don't think "how many" means a darn thing.

All the Police cars and Taxi cabs were COPO ordered.
I am SURE those were not one off's.
Here is how Ed Cunneen describes a COPO car on his ZL-1 site:
"INTRODUCTION
COPO stands for Central Office Production Order. Chevrolet dealers would contact the Central Office in Michigan to request deviations from regular production options that were available for the model year. For instance, special color paint could be requested for an additional charge. Generally, options that were requested had to be in current production for other models. Chevrolet engineering then had to grant approval for these vehicle parts combinations.
These types of orders would eventually become instrumental in laying the groundwork to build factory race cars."
Seems to me that ALL the special ordered 67 IPC cars are COPOs,
Especially the 11 Canadian BB IPC's.