Excellent note Dave..beautiful engravings! The US Specimen notes usually have thw SN 12345678 with the word "SPECIMEN" in bold red letters. These notes are quite expensive as they tend to run in the $5-$7K range. RB
Several of them are offered here, for example. Note that the usual serial number is 23456789, not 12345678.
I was at a Chase bank ATM today withdrawing some cash and noticed the graphics on the screen, when dispensing cash for a withdraw, depicts an image of $20 notes that bear a red "specimen" notation and the SNs are: EE 00000000 D. I didn't catch the Series date, but they are the redesigned notes of 2004-present.
I thought I heard someone mention American Bank Note Speciman notes, and I remembered having one somewhere in my scans. I see these on eBay in GREEN and BLACK.
dang, they do get pricey. That Barr specimen would look cool in my collection or even a Webnote Specimen lol i need to wake up, this dream is getting pricey!