Bumper identification - smooth/no groove 33-36?

[38 coupe]

These days I keep seeing old Argentina repop crap being presented as NOS by people who didn't experience it the first time. I wasn't around in the 70s, but I remember the mid 80s and on, and all the V8ers who were replacing the Argentina parts on their restorations when decent parts came available.
Discount the observations of the best advisors at your discretion.