1864 Csa $20 Note... Genuine?

Looks authentic to me. The serial isn't on the known fake list and the signatures are signed, not printed. Cuhaj's book (Confederate States Paper Money) lists it as a T-67. The vignette is of the Tennessee State Capitol and the bust is of Alexander H. Stevens, Confederate Vice-President. Value is $20 in Good up to $70 in Uncirculated. 4,297,000 of these notes were printed. I don't see any reference to the lower margin character but I am guessing that it is a printers plate position letter which wouldn't change its value either way.