Scott#551 (4 sheets full pane. #20371).

Another way to tell: Scott #551 would have a Plate Block of 6 and Scott #653 would have a Plate Block of 4.

Plate #20371 was only used for #653 not #551.

Scott#551 (4 sheets full pane. #20371).

I have 6 sheets of these maybe more #551

I have some partial sheets of scott #551 and 562 if there are 3-4 stamps missing from the sheet is it better to break it up into blocks of 4-6 or pairs ? Or sell the partial sheet