Hamilton 806015-4 with a grade 806 movement

[Namespetra]

Has anyone come across a 17 jewel grade 806 movement? This watch looks like a hybrid of the 1972 Sea Beach IV (dial) and the 1972 Sea Cliff IV (case) but the exterior case back number and the movement grade are different from other models of the period. The lug width is 18mm and the case has an exterior imprint that seems to show a maker's mark next to the gold plate (20 microns) information.
I tend to think that it's a genuine model instead of a franken. Perhaps extra dials, cases and movements were assembled to create a new model? A new case and movement grade number could have been then assigned to indicate that a change was made and a new model created.

[Dave]

Into the case number thread it goes until we can find further information.