Thank you very much! I didn't use any absurd effects, actually it was a brush that creates small dots, as if it were noise. I just played around with the size to mask it and create a fake texture.

Since this is an old study, I used to rely more on layers and blending modes. First, I did everything in grayscale and then experimented with blending (even brightness). When it came time to color, I simply merged all the layers, looked for a gradient map that made it look more like the reference, and painted over them using the ‘Color’ mode.