the shop where we bought many years ago in Spain told me that the year is 1969-1970, Seamaster Genève, very rare model
Why do you say it’s rare? The fact it’s 18ct?
because in the dial say geneve and back say seamaster , yes it is 18 kt
I suspect that it is pretty uncommon to find a later Geneve like this in 18k gold. This model, with the utilitarian case style, was more typically an entry-level piece, IIRC.
I don't think that the particular combination of Geneve and Seamaster was so unusual. There was a lot of co-branding of the model lines in the 60s. You can find almost any combination if you spend enough time looking.