That's a Valjoux 7733 movement - used in a lot of Swiss watches in the 70s, including Tissot. I still don't think this is an original Heuer. I think someone has created that dial and put it in another watch. I also believe that Heuer has been etched on the bridge by whoever created it, not by Heuer. I think it's very unlikely you're sitting on some undiscovered model and don't think this has a lot of value I'm afraid.