187's 188's And Secret Marks

Hi all. I ran across these stamps earlier and the envelope they were in had them labeled as 188. I stumbled upon an article saying about 188's have a secret mark and 187's are same stamp but without the mark. I took some pics under the microscope and I am having a tough time making one stamp out. I would like your opinions on the pics. I thank you in advance.


Here is single stamp under microscope



Here is left stamp of the pair



Here is right stamp of the pair

BakerJ...the bottom photo is a #188....the one with the semi-circle in the right hand scroll....others appear to be #187

BakerJ....also....what stamp has the semi circle mark? If it is in the bottom pair....DO NOT SEPERATE. Even thou the left stamp is damaged it would be a combination pair #187/188....SCARCE and hard to find.

BakerJ...after looking again....looks like it is in the pair, right stamp (just trying to judge from cancellations)

I don't see a mark in the first photo. In your second photo, the mark is very faint but there. The third photo has an obvious secret mark.

Agree with wkusa. Secret mark in both stamps of bottom pair ... no secret mark in top stamp.

Hard to say but it looks like there might be a trace of the secret mark in the left stamp of the pair. very far right of the semi circle seems to be there. need a sharper scan or photo. But if any brown ink in that circle, then it is a 188

Sometime getting closer hurts more than it helps.
Don

Thanks guys!