Mick,
I don't know mate.. I've never seen similar markings. Hopefully someone can come up with better info than me!

Stewart

: Hi Stewart,

: Thanks for your help.

: I know the Cuanillon markings.

: In this case it ought to be a rather small market, I did never see
: similar engravings on other Heuer watches.

: The NN-N format lets me think of week-of-the-year and
: day-of-the-week or total number of a set and ordinal number. Any
: further ideas?

: Cheers,

: Mick