I was tightening up the lower heater hose clamp to the water pump today and had to remove the idler pulley assembly. So I finally got a photo of the EUN on the front of the block that is hidden by the idler bracket. The car was ordered by Enrico Stein on 05/09/1973, shipped on 07/19/1973 and delivered to him on 07/31/1973.
Here you go:
