Help Needed On Identification Of US Philippine Stamp Nib?

Hello all. I am new here and decided to start off with a stamp I am either too dense to find in the cataloges, or online, or maybe I have an error. Your help would be much appreciated.

By what I can find this one should be anywhere from deep green to yellow green depending on year of issue. There are also different watermarks as well. I attempted to find the watermark and ther might have been a slight single line "s", but I am not totally positive because it could have been formed to appear because of the color on the other side and a slight thin area. Also the "s", if there, was on the right side of the stamp and I believe there should have been more letters before that with the room to the left. Again not positive either way.

The number I found for this are 241, 261, 276, 285, 290, and 340. All of these are in the green range of color specifics, with 340 being imper. The stamp is 12 perf. so that only leaves me with 261 as the choice, but again it is not the correct color. I must be missing something somewhere.

If you look close you can see a tiny area on the bottom right of the stamp above the "2" that does show a slight yellow green/green color, but the rest of the stamp is a deep blue. The ten cent stamp of Lawton is the only other one supposedly blue in the group. Wrong denom. and wrong person.

Again any help would be very much appreciated on this. Now I will have a look around. I have many more questions coming I am sure.

Thank you,

SP

welcome sirruspoe. Cant help with the ID on that one, but just wanted to let you know people will be seeing it and you will very likely get your answer shortly. Again - Welcome. - jeff

Thank you Jeff. I am looking around have already learned some stuff I had no ideas about being new to stamps and all. The thread on fakes from ebay was very interesting.

The catalog says deep green for it, but looking in teh catalog, it's fairly "blue-ish"

Thank you for the response Dave. I also noticed that in my cataloge from 2006/2007, but then I compared this particular stamp with another blue regular US stamp and the color matches really close to the color of A160 number 557, but matching closer in color to the 637 issue, but might be even a little darker in color than that. Thank you again for the help.

Hi sirruspoe. Welcome to the site. I'm wondering if this is what's referred to as a changeling? I do see that area of green and it leads me to believe that ink has been changed either through chemical reaction with something it's come into contact with, or something in the air while the stamp has been stored. There are others on this site who are more enlightened about these things than I am, and I'm sure they can lend their expertise.
Those are my thoughts anyway.

Thank you James. Could be a likely answer as I am no expert. I do have the same stamp in the proper color which was stored side by side with this one for at least the past 30 to 40 years in an stamp album, but the changing could have happened before then. Thank you for the insightful help: I never would have thought of that even though I read about the subject a ways back.

Yes, file under chemical and or light damage,
this is a fairly consistant pigment change in stamps
of this colour.

Thank you Rod. And everyone else. We will call this one solved. Great help I appreciate it all.