Dąbrowski has an unidentified “American Masonic Symbols”, see below. There are quite a few symbols on it that are unfamiliar to me, such as this one. I don’t know in what rite or degree this symbol is of significance.
It could be that the coiled snake is another version of the coiled rope. Here we have a suggestion that the snake and the rope are interchangeable.
There is a coiled snake (though three headed) on this 21th degree AASR apron (1893 Vermont).
I also have a 19th degree AASR emblem with a three headed snake.
Top: Dąbrowski p. 160 “Symbols of American Freemasonry”
Bottom: The Book Of The Ancient And Accepted Scottish Rite (1884) Charles McClenachan