None of these 1p stamps are from the clay printing. They are all most likely 1E3. All four covers have plastic censorship tape and were postmarked in Buenos Aires.
This stamp has a lot of over-inking of the frame plate.
The sender of this cover made a note for the censor that the letter was written in English.
Notice the difference between a non-clay paper (the 1p value) and a clay paper (the 5c).
This third cover has a slogan postmark.
The slogan reads "1821 General San Martin makes his triumphal entrance in Lima."
Notice the difference between a non-clay paper (the 1p value) and a clay paper (the 5c).
Notice the difference between a non-clay paper (the 1p value) and a clay paper (the 5c).
The 1p has a noticeable plate variety.
