#25 W/Strong Line On Shoulder. Recut?

All the lines on the shoulder are worn except this vertical arced line. I don't think it's a recut line but is it a particular plate characteristic?

It's a normal stamp. Here is a clearly printed 3c stamp for reference.

Winston, of course. But what I'm seeing is the one strong line remaining when all the others are worn.

Every engraved line is a little different. Some are deep, some are shallow. As a plate wears, the deeper lines become more accentuated because others have faded away.

That seems especially true in the neck and shoulder area.
I guess my hope was with this line, it might be something that distinguishes plates 6, 7 or 8 from each other.

Beautiful #10A, sinclair2010! Looks like a proof.

Am I out in left field on that?

Yes. The best way to distinguish Plate 6/7 stamps from Plate 8 stamps is to look at the bottom line. Plate 8 stamps will have a heavily recut bottom line compared to the much more lightly recut bottom line of Plate 6/7 stamps. Plate 8 stamps generally have all four framelines heavily recut with the exception of the top row of course. Also, the framelines on Plate 8 stamps will frequently not meet or overshoot in one direction or the other at the corners.

As always, Thanks!