The first piece also bears a 50c2C-SO.
Here is the 1p stamp.
And here is a detail of the overprint.
The second piece has a 2pNGR-SO and a pair of the 25cCL-SO, the clay printing.
Here is a detail of the 1p stamp.
And here is a detail of the overprint showing doubling.
The 2 pesos has an overprint with a minor break to the V of SERVICIO.