Some things I find interesting.
 Hope you also do....

 
Dummy Testing Coils with Purple Defacement Lines

Shown below are additional examples of purple defacement lines on tagged Cottrell press FTPO coils.  Because some of these examples are only pairs, several could be from the same printing.  Longer strips, 12 or more stamps, would be needed to show a complete revolution of a usually sized Cottrell mat... if these defacement lines were indeed actually applied on the Cottrell press. 

It is still unknown if these defacement lines were added by BEP, the USPS or others.

To more easily see differences, examples are at 300%, scanned at 75 dpi and saved as jpgs at 90 quality.  Thank you for your patience while the page loads. 

This first example has two widely spaced lines with what looks to be uneven inking. This line pair also has a horizontal scribe line on stamp number two.

 
 
Four thinner non-uniform lines are on this pair.

 
 
Shown here are five narrower incomplete lines with several vertical lines on stamp number one. 

 
 
This longer line strip has six lines very similar to the lines on the previous pair.

 
This is an initial attempt to document for collectors the different defacement lines which can be found on the Cottrell press tagged FTPO coils.  This is NOT meant to be an exhaustive catalog of what exists.

Surely, other types of defacement lines must exist in other collections. 

If you know of, or have examples of others,  I would appreciate the information and will gladly post scans of your coils giving you full credit.

Hope to hear from you