[drcy]

As noted, the black light test is a test (that this item passed, and the item had to pass) but not in and of itself proof.

The back of the stock obviously looks old, even from the photos, so the only question was if the front was another layer pasted to it-- which chances are would fluoresce.
While the test in and of itself is not proof of authenticity, I would imagine that 90+ percent of reprints/modern would fluoresce brightly. Meaning, yes, it is possible for a reprint or fake to not fluoresce, but most will be identified by the blacklight.

Also, as already noted, I looked at closeups of the printing-- why I made my original opinion-- and this item was made with the period and no longer commercially used printing process. If someone were to ask me, I can give them one of the images and explain what details led to me coming to that conclusion. ​

As I already said, authentication involves looking at a variety of information. However, the number one thing I look at is the printing. Antique commercial items such as this were made with specific, and no longer commercially used, printing processes that can be identified under microscopic or enlarged image examination.

I told Paul in PM that I assumed the item would pass the black light test, and it did.

While the funky staining on the front made me too wonder when I first saw the image, I don't think that's at all issue. If, as someone proposed, someone went through the elaborate process of getting an old printer (How this would be done, I don't know, and the printing would cost a lot more than the price of the ad, and would only be financially feasible if you printed hundreds of them) and old optical brighteners-free stock, they wouldn't then fake tone & age it in such an obviously funky way.