Figured I'd share this... It was found in Florida and turned in to the authorities. I don't think it would take much fine-tuning for this thing to pass.
i use to work at a bank and i got counterfeit notes on a weekly basis. 5's, 10's, 20's, 50's and 100's. most of them were copies made with printers. from a distance they looked ok. up close was a different story. some were so bad that even if water dripped on them the ink would run. we had a few of the bleached $5's that had 100's printed on them. we did have to send them in to the feds.
I recovered a similar note to the one in the OP early last year. The Secret Service gladly took it off my hands, after I heard the penalty if you're caught with such a note - you could be held liable for the note's production if you can't supply sufficient evidence that you recovered it from circulation. Sure wish I had take a pic of it though, to see if perhaps the serial number was identical to the OP's (counterfeit bills often bear the same serial number). The note I recovered looked fine at first and even second glance, but when I ran my finger over the thing, it felt all wrong. Although I believe it was printed on some sort of fabric, the material didn't have the same crispness (for lack of a better term) as the rag paper the Federal Reserve uses.
There is no way regular people without sophisticated technology can fake a new style 20. The US Secret Service produces a pamphlet called "Know Your Money" There are exactly 8 points of reference to determine authenticity.
Well I assumed that too, but I was just making sure. Thats what it looks like after several glances to me too, and it obviously makes sense to be COUNTERFEIT
On another side note, I wonder how they made this example and how it was detected back in 1928. I dont think they had the fancy holograms and strips back in the day.