from the beginnings in 1942, this seems to be their only one crest, so..not too much to start....i used a similar, slightly modernized shape, a circle with the initials CANP, but a simple, minimal form, not the old, river plate look alike. I also used the Potosi flag, flipped to match the old diagonal stripe. I tough using other details and elements such as club's full name, or the foudation year, but i wanted to keep the simplicity of the crest.

I really like the way you got inspiration from the flag of Potosi.
this crest is for sure better than the River inspired one.
It's ok that the initials form is different, but looks too much simple.