Looks like a Landeron for sure.
Check this out.

Translation:
Breitling found to the still present movements 178 Venus of the 50s
some cases 18 carat rose gold from the same period and could
finish this results in a small series of 50 according to the attached figure.
For the German market we have total 10 items available.
The net price is DM 4800, - + VAT - 3% cash discount for payment within 8 days. Supply only against firm order.
The few pieces will be soon sold out and we advise of prompt disposition.
[img]http://www.MyEasyPics.com/is.php?i=808378&img=82_31053_5[1].jpg[/img]
The cases all appear to be the same but with different engraving on the back.