Here is a recent $51 buy. It is a ~1921 Burlington Watch Co. 16s, 21J, Grade 107, S/N 3955579. They made a boatload of these. It appears to be in the original (tired) Burlington case and was owned at one time by D. von Dolson. The mainspring is broken, but the balance swings freely. Probably just needs a mainspring and a good cleaning.