Hi Sebastian
There is good reason why you have not found this watch in any Heuer literature and that is because it is not a watch Heuer made. More precisely, the dial is a bad fake. The crown may be original so too could some other parts but apart from that this is a poor attempt at faking a vintage Heuer. Value is therefore zero to any collector which I assume is what you wanted to find out. There may be a few pounds/dollars/euro in parts but thats about it as far as I am concerned.
regards
Paul
www.heuerworld.com