Mid 50s Elgin Automatic 6823 Cavalier
This Elgin is probably from 1955 and likely debuted along with the similar looking Niagara. I was told it is the Cavalier.
This model, with case number 6823, is 10k gold filled and has a nicely machine decorated bezel.
The dial has a nicely done, pressed, Sunray design, with gold drilled minute markers and raised gold hour markers.
It uses the 17 jewel, Swiss sourced 643 automatic movement.
Also, note the hands. When I first received the watch, I just assumed it was fitted with improper hands, but I came into possession of another 6823 and it has the same unusual hands.