I originally saw 1831 as well, but looking at the width of the confirmed "8" in 1685, the various "6"s on the chart are noticeably narrower. I'm very swayed to it being 1631
Agree. Viewed in isolation, one could make a case for '8' but, in situ, with the other numbers on the chart considered, it's '6' for me.
Having reviewed the images, I concur that it certainly looks like 1831 in one of the faded-red images. I did all kinds of zooming on that pic to try to find a discontinuity in the right upper vertical and it was illusory at best.
However, that's also the image which shows a funny black blob emerging from the upper right of the 9 in 1709 just above it.
It's also part of the darker series of digits anyway, which, due to the lighting, look to be of heavier line weight than lower digits, even though I'm sure they're exactly the same in reality.
As such, even though I am perfectly content with registries even up into and beyond the 1900s at this point in the chronology due to later works, meaning I have no philosophical problem with 1831, I'm nonetheless sticking to 1631 as per my previous deskew results that seemed to show that on the remaster, the number width observations, and Jein's view of a less aged film.
Also, I hate to throw shade at the OGs, and I realize typeface availability and the effort to create such things is just easy-peasy now versus then, but I would like to reiterate once again . . . dear sweet heavens there had to be something better available. I whipped up some 8 point stuff in Wordpad, zoomed out 50%, and screenshotted . . . this was the result, and they're all fairly easy to read except Helvetica.
(The custom Iosevka font kinda resembles the ST2 tactical graphics digits, which were pretty dang awesome. Also, I neglected to note that the Routed Gothic is my modified tabular version, hence the monospace digits.)
Wouldn't it have been amazing not to have to zoom and squint and such for almost 60 years?