Actually 64 is even more fun and is a great example that I wasn't aware of.
This is why I love big, "common" banks. Often lots going on at a relatively low economic cost (except for time researching which generally isn't a cost at all). I'm sure you know all this Doc, but I wanted to document it so I can find this example later. As originally written, the NB Act forced the bank to liquidate in 1882 and form a new bank with a new charter (2715). This anomaly in the law was quickly corrected so my 170 (3rd NB of STL) which was organized less than a year later avoided this exercise altogether, just going through normal charter extensions every 20 years. 170 kept its charter number throughout and only changed its name due to a merger in 1919. At any rate, the Milwaukee bank was able to regain its original charter number in 1911 and name (The First NB of Milwaukee). Interestingly, its new dated back series of 1902 notes still carried the first 20 year extension date of 2715 (April 25, 1902). In 1919. 4817 and 64 were consolidated/merged under charter 64 with the First Wisconsin title (as on your $20). Since charter 64 was the survivor, the 1902 charter date continued to be appropriate to appear on its plain back notes for its last 3 years before extension in 1922 (your $10). And despite the dates, the treasury serials indicate that your 2 notes were printed within 4 years of each other: the $20 in late summer 1919 (just after the name change) and the $10 in early 1923. What fun!
Always interested in St Louis MO & IL metro and Evansville IN paper money, scrip, financial docs, banking ephemera, etc. Also collect Latvian 1915 - 1940 city and national paper money by block letter/variety