for sure a 69 plate. ElCo should have a commercial plate also when new, unless special request from the buyer.

So at sometime in the last 25 years the car was reregistered under the
"YOM"program, Year of manufacture plates can be placed on this El Camino
and they could have used Commercial Plates or Passenger car plates, makes
no difference. As long as someone walks into DMV with black plates and a year
sticker on the plate that is the same year as the car, or truck in this case, its a
done deal.

Thanks for the info SPEEDYB!