:::: For the dates, I used http://www.uspapermoney.info/sign/registers.html and http://www.uspapermoney.info/sign/treasurers.html to get the dates for the Registers of the Treasury and United States Treasurers.  "A Guidebook of United States Paper Money (3rd edition)" by Arthur and Ira Friedberg explained the difference between a FRN and a FRBN, as well as showing the signature combinations.  The last one listed is Elliot/Burke