There is rare and rare. Only the 2nd time I own one of these and they are always surprisingly impressive in size.  This one is all original with original crowns and looks just great. The watch is in good overall condition with nice even patina. Inner bezel works well and movement is well preserved. 
 
Details:
 
Brand: Nivada Grenchen
Model: Depthomatic
Reference: 57023
Year: 1968 Approximation
Material: Stainless Steel
Dimensions:  43mm
Crystal:  Plexiglass
Movement: Automatic
Bracelet/Strap: Vintage Tropic 22mm Strap
Box/Papers: No/No