A few more...
As freddy333 pointed out, the coronet and triplock stampings on the exterior of the crown are more defined and sharp/precise-
But, the other characteristics that will identify a genuine 703 Triplock are:
1) The opening of the crown where it fits over the tube- The genuine Triplock tube is quite large at the base diameter where the gasket sits.
As such, the crown has to have an opening large enough to accomodate. This picture shows just how large the opening is-
***Note that the opening starts at the base of the bevel- Rep crowns use smaller diameter tubes and hence require a crown with a smaller diameter opening. You'd see the crown's bevel and then a flat edge at the base before the opening...
Here is a comparison... See the difference?
2) The 'cut' of the ridges are much more defined on a genuine crown, and the profile is typically much shorter on the gen as well (rep crowns are too 'tall'). Compare these pics...
In this pic, notice how flat the tops of the crown ridges are.
Same watch (after mods)... Now with a gen crown-
Nice, sharp, pointy ridges...
And, as freddy mentioned, the feel of the crown is much better as well. Much smoother when unthreading from the tube... Much more confidence inspiring...