I think, I can add some additional pics of another watch like that (not exact similiar).
A friend of mine has send me a pic some weeks ago:

He could not evaluate this kind of watch.
Another friend of him has bought this watch at a flea market from first owner, the first owner sais, it was a present from 70s.
I asked him to send me better pics, specially from the dial.
I was interested in that watch.

You can see the scratchy crystal and the sign over the former (big) brandname.

In the meantime, my friend bought the watch and has made some better pics after polishing the crystal:

In the moment, the watch is at the watchmaker for a service, he said.

What can I tell you about the watch:
Probably the parts, I can see, are all Heuer parts?!
The case is a 73663, the fluted pusher and the Heuer crown are genuine.
The crystal has scratches as one might expect at an old watch.
The orange sign over the brand seems to have same colour as the hands (old orange).
That is the state of my knowledge.
Hope, my friend and me, we can get some answers here (about the sign or about a possible brand).
Thanks in advance,
Peter