A fuller explanation of the 1d red dieII *that is not a die* but a constant printing flaw. It is very interesting because there is nothing else like it.
The printing wheel for columns 2 & 3, in a cast for 10 stamps per wheel, had this flaw [die II] in varying shapes & angles before the spur broke off. The spur lasted for 2 complete printing wheels then broke away from the mold.
There was an extremely small printing of dieII 1d greens before it was corrected. Stamp positioning is the only way to identify this flaw in the 1d greens.

My prize collection of progressive dieIIs. Even in the condition they're in they are very expensive stamps because of shade & perf "OS". Magnified examples below:

Merged flaw. Bottom stamp 2nd column. One only in this state.

Intermediate flaw. Second stamp from bottom on column 2. One only in this state.

10 recumbent flaws at varying degrees of angle spread over columns 2 & 3.

8 erect flaws at varying degrees of angle, third column only.