If this stamp belongs to you, you're going to think this way??
Shi.(Many apologies. I tried to post in Mandarin but the forum changed the characters into Japanese kanji.)
I am uncertain what the term in Chinese philately is, but in English, we use the word "flyspecking"
for how you are looking at your stamps. No American or European catalogue lists such minor variants because they are problems with the process of printing. They are not errors in the engraving of the stamp plate.
I will examine my stamps of this issue for similar variety this morning and if I discover anything I will post pictures for you and all to see. The fact remains truthful that what you have posted here are interesting printing variations but they add little-to-nothing in the way of value.