Be careful not to mistake a 51 for a 57. I had one where the top line of the 5 joined the 1 to make it look like a modern 7. It was mainly because it was a jump in the temperature that I looked closely and saw that it did not look like a 1916 7, and then realized what had happened.
Sorry, I did not think about this list when I found it. I will keep an eye open for another example.
OK here is a 51 (previous and subsequent temperatures were 52, so I am fairly confident that this is 51 and not 57 - Also, the 1 doesn't go below the line like the 7's) and two 7's and a 57.