you collect all informations about the watch you are looking for - specially if it is a vintage watch.
Please do this for your wanted watch - the 5402 ST- generelly.
about what i wrote and what you write. Your last chance!
You write:" it looks quite new to me". How can you come to this conclusion???, if there is only the "royal oak" engraving left!!!
I told you about the deepneth from engraving.
That the watch had a revision is really good. But think about, if the watch is authenic. Wempe only can do it´s work on the baseline,
that depends on the watch they became from the consumer. I, personally really have no problem with vintage watches with signs
of using and you are right - the watch is nearly 40 years old. Bur no engraved number ???
What did the seller can tell you about engraving.
regards
Stephan
and the not engraved number - about what you will pay for a watch like this

regards
Stephan
Let's not jump to conclusions, Stephan. Believe ye me, there are definitely a few genuine A series 5402s out there with 'Royal Oak' only engraved on the case back, sans number...