I am not sure if the Red Writing = 998 or 866. The red writing is on 60 out of the 90 pieces I have. The other items seem to be missing the red writing entirely, while others have little fragments of red, as if the original red marking has worn off over time.

Also, some of the pieces show an impressed makers mark that just says "Copeland" while a few other pieces have an impression of the "Copeland" maker's mark at the top of the impression, and then a capital B below that in the same impressed stamp.

I am not sure if the red lettering is associated to the print name, but I thought I would share in case this helps!