R135 - Is There A Color Variety?

Still going through batch of revenues and came across page with approx. 100 R1235 revenue stamps, including these:


Most look like the one on the left. But there are several which have parts in a dark brown (center). I cannot find a variety listing, so not sure how this happened. The one on the right appears to have some type of grid cancellation, back of stamp shown below.

R135 Orange and Black
R135a Vermilion and Black
R151 Orange and Black on green paper

Your 1st stamp could be either R135 or R135a
2nd stamp is R151 the Orange pigment is unstable and does oxidize
3rd is R151 Orange and Black on green paper (R135 is also an unstable pigment)

Thanks very much, revstampman. Looking back at the stamps, your answer turned on the lightbulb in my mind !
The solid orange areas have oxidized the most which makes the coloration look intentional.

Is that on silk paper? (the one showing the obverse.)

Yes, it is on green silk paper. Not to be confused with the "Experimental Silk Paper"

R135 versus R135a is impossible to tell from scans, as the difference can be subtle.

The best way to get an idea if you might have an R135a (vermilion) is to put the stamp right next to an R145, which is also vermilion. If the colors match EXACTLY, odds are it is the R135a.

Certification is absolutely required for resale; no one in their right mind would ever buy one without a cert, as far too many people think they have "the valuable one" when all they have is an R135 with a slightly more crimson shade than the normal orange.

My example of R135a:

http://www.revenue-collector.com/pages/1237.html

I picked up two of them with PF certs in the same Spink/Shreves auction back in 2009, both from the Cunliffe collection. I kept the nicer of the two and sold the other one to Frank Bachenheimer (I believe he still has it if anyone's looking for a certed R135a).

Thanks to everyone for your input! It is obvious that study revenues can be just as elusive as regular postage research.