The rear case on all Monacos should have the same star burst grinding on all four coners and longditudinal grinding on the centre case. Tool No 033 and heuer should always be stamped. Note only exceptional examples look as good as this. Most are more worn.
As above but between the top lugs there should be serial numbers. Check our register page for examples of numbers. Always 6 digits, ranging between 157xxx and 26xxxx. On PVD models you will need a loupe to view.
As above view note crisp adges on the pushers side. Also note the grinding contrasts with the high polished sections.
Model numbers should always be engraved (normally on the bottom lug). 1133,73633, 1533, 740303. Often they are much less visible than this due to wear and if they look too uniform and deep may be re stamped. No serials = avoid!
Side on lug view, again note grinding and crisp edges of this nos example. The crown should always be stamped.