1959 Constellation reference 14381. This is a rare variant with the factory luminous package - note the radium lume dots on top of the arrowhead markers at the 1,2,4,5,7,8,10 and 11 positions.
Seikomatic: good size, subtle fluted bezel, nice sunray slate grey face, day/date (not changed for today), hidden crown... I reckon these are great value for money.