Help Sc#634 Crack Plate?

I have obtained this copy that I have identified as an SC#634 and upon examining it a question arose. The fact is that upon observing it carefully I have seen that it has numerous white flaw that do not correspond to a chip or tear, they can be seen within the oval of both figures, under the letters of "CENTS" and between the letters "POSTAGE" . My question is, crack plate?

That runs under "ink scooping".
In general, all plates deteriorated during pinting. That means the grooves on the steel plates got shallower over time.
In larger areas which should appear in a solid color, that could result in ink being removed by the plate wiping cloth, resulting in random white specks. Notice on your stamp, only the ovals where the digits are placed and the arc where the writing is placed are uniformly red, and these are the places where random ink thingies usually occured.

Great!! Very Thanks!!