US Gutter Pairs Of Benjamin Franklin One Cent Green And George Washington 2 Cent Carmine

Hi littleriverPhil. yes, I did and both are 3mmm.in width above.

Ah, thought so, the center margin looked wider the margins on the outer sides of the pairs.

That is why when I viewed them I had considered them gutters due to width being larger than normal pairs. It can be also viewed in the visual comparison with the "Harding pairs". The width is larger than the pair he has in his possession too.
Thank you for your great observation. I have been told in past, they are special stamps.

It is odd, they are listed as 3mm but have no sub lettering or numbers.

The #343 pair, with 3mm spacing, is from a "Star" plate, from the outer 6 rows on the sheet of 100. There were issues with shrinkage causing miss-perforation with the 3rd. bureau issues. They were first issued with uniform 2mm spacing, which was deemed unsatisfactory (causing miss-perforation issues, causing too much waste). These first plates were plate numbered along with the Bureau of Engraving and Printing logo. The spacing was changed to 3mm for the outer 6 rows and 2mm for the 4 inner rows on each of the 100 (10x10 rows) sheets in the 4 sheet printing format. This change was given a small open star, plate number, and bureau logo. There is also one sheet of #343 from plate #4980 with a small solid star that has the same spacing as stated above. This spacing caused problems for the private vending and affixing machine manufacturers who required equal spacing between rows on unperforated sheet stamps to work in their machines. Finally a 2.75mm even spacing was used. These sheets had an "A", followed by the plate number then the Bureau logo. As the first plates and the stared plates were retired, the remaining plate produced with 2.75mm spacing dropped the "A" from the plate number. The "A" plates were not used for #343; they were used on #383. I think I got this right. If not, someone with correct me.

Whew! As if W/F issues aren't complicated enough! So, ideally one would want strips showing both 2 mm and 3 mm margins. Easier to find the star plate number.

Excellent information Al. I do believe your information is correct from what I read in the past. Thank you for sharing it in the forum.
Below are other photographs I would like to share with the room pertaining to 3 mm and 2mm differences.
This is a block of 6 Washington 332's that are also 3mms as well. I always look at the perforations carefully between stamps with the Scott's 332's. If you line them up on a 2mm, they are not the same width size. The perforations are not directly in the middle between stamps. In the block of 6, in the top margin is also have the pin holes.
The Benjamin Franklin block of 4 also came along with the collection of unused stamps.

Those are not sheet stamps, they are booklet stamps. Therefore they are not blocks of 331 and 332 but booklet panes or portions thereof.

Thank you Rhett for the clarification

The perforations start from top of margin down. Stamps from booklets show this. I just thought I would share some examples of perforation differences.