vent de montre rolex en finland

The Rolex website does not provide a list of Rolex dealers, but a
fairly recent message at http://www.qahill.com/tz/cities/helsinki.html
lists several Rolex dealers in Helsinki/Helsingfors:

- Westerback (Mikonkatu 3/Eerikinkatu 7), http://www.westerback.fi/
- Tillander (Aleksanterinkatu 48), http://www.tillander.fi/

Note that the given websites are in Finnish only.  At
http://www.tillander.fi/index_myyjat.html you can find a clickable map
that gives you the opportunity to locate Tillander's other branches. 
I have not been able to check if any of these sell Rolex watches.

Search term used on Google:
"rolex dealer" OR "rolex shop" finland OR suomi OR helsinki OR
helsingfors