Don't do it!

movimento Rolex Explorer I cal. 1030

A case already seen that we examine in more detail: a movement of an Explorer I with surprise.

movimento rolex explorer I senza automatico

We remove the automatic.

Punzonatura ponte Rolex

Now, after checking that it is not loaded, we remove the rochet, and we find the "surprise".

Rolex Explorer ponte bariletto punzonato

As the barrel bridge had the oval hole, someone has seen fit to use a shortcut to "solve" the problem.
Probably remembering old (and unorthodox in many of the cases in which they were used) methods used to clocks type has seen fit to give a punched the bridge in order to bring a bit 'of material which lacked.

Ponte Rolex punzonato dettaglio

The result, more closely.

(Click to enlarge)